KR20160101458A - Method and device for eliminating a cancer cell and preventing a cancer cell recurrence using piezoelectric element composed of organic ferroelectric material - Google Patents

Abstract

The present invention relates to a method and an apparatus for removing cancer cells and preventing cancer cell generation using a piezoelectric element composed of an organic ferroelectric material. In a piezoelectric element used to prevent the regeneration of cancer cells in association with an embodiment of the present invention, the piezoelectric element is located in at least a portion of a subject receiving a surgery for removing the cancer cells, vibrates by an electric signal induced from the human body, and prevents the reoccurrence of the removed cancer using the vibration. The piezoelectric element may be composed of an inorganic ferroelectric material and a mixture of a metal and an organic material.

Description

FIELD OF THE INVENTION The present invention relates to a method and apparatus for removing a cancer cell using a piezoelectric element composed of an organic ferroelectric material,

The present invention relates to a method and apparatus for removing and preventing cancer cells using a piezoelectric element composed of an organic ferroelectric material.

According to the Ministry of Health and Welfare, the number of patients suffering from cancer is about 490,000 as of 2007, and the number of patients newly diagnosed with cancer is about 150,000, and the number of patients is continuously increasing every year.

The risk of cumulative cancer development in men by survival to life expectancy is 32%, one in three, and the risk of developing cumulative cancer in women is 26%, which is known to occur in one out of every four people.

Most cancers are difficult to cure without early detection, and some cancers such as pancreatic cancer are known to have poor prognosis after treatment, even if detected early.

Regular screening is the most important to reduce cancer deaths, and regular care for recurrence after cancer surgery is as important as preventive screening.

In the World Health Organization, one third of cancers can be prevented, one third can be cured by early diagnosis and early treatment, and the remaining one third cancers can be alleviated by appropriate treatment. The ultimate way to combat cancer is known to prevent cancer by early detection through routine screening and by practice of healthy lifestyles such as smoking cessation and weight control.

However, there are still many technical difficulties in predicting recurrence after cancer surgery and setting the direction of treatment, and there is no examination or prediction method to detect recurrence of cancer, There is controversy over the clinical efficacy.

Therefore, it is possible to efficiently detect and remove the whole blood in the body through the sensor, which can predict the possibility of cancer metastasis and the type of recurrent cancer and provide important information for the determination of various cancer treatment methods. And an apparatus and a method are required.

Korea Intellectual Property Office Publication No. 10-2010-0045831

It is an object of the present invention to provide a method and apparatus for preventing and eliminating cancer cells using a piezoelectric device composed of an organic ferroelectric material. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. It can be understood.

In order to achieve the above-mentioned object, there is provided a piezoelectric element used for preventing the recurrence of a cancer cell, which is related to an example of the present invention, for realizing the above-mentioned object, wherein the piezoelectric element is located at least in a part of the object, The vibration is used to prevent the removed arm from recurring, and the piezoelectric element can be composed of a mixture of an inorganic ferroelectric material and a metal and an organic material.

In addition, the inorganic ferroelectric material may include at least one of an oxide ferroelectric, a fluoride ferroelectric, a ferroelectric semiconductor, and a mixture of these inorganic materials.

In addition, the inorganic ferroelectric material may be PZT.

The organic material may be a polymeric ferroelectric material.

In addition, the polymer ferroelectric may be selected from the group consisting of polyvinylidene fluoride (PVDF), a polymer containing PVDF, a copolymer containing PVDF, a terpolymer containing PVDF, an odd number of nylons, a cyano polymer, Or the like.

Further, the ferroelectric substance can be used as a material of a ferroelectric transistor or a ferroelectric memory.

The piezoelectric element may further comprise: a main component containing a perovskite-type metal oxide represented by the following general formula (1); Mn as the first subcomponent; Li as the second subcomponent; And Bi as a third subcomponent, wherein the Mn content is 0.04 parts by weight or more and 0.36 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 wt% 0.0280 parts by weight or less, and the Bi content beta is 0.042 part by weight or more and 0.850 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the contents a and b are 0.5? (? MB) / 1 (wherein ML represents the atomic weight of Li, and MB represents the atomic weight of Bi).

≪ Formula 1 >

(Ba1-xCax) a (Ti1-y-zZrSnz) O3 wherein x, y, z and a are 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02 and 0.986? A? Lt; / RTI >

Further, the fourth subcomponent further includes at least one of Si and B, wherein the content of the fourth subcomponent is 0.001 to 4.000 parts by weight, calculated as metal, based on 100 parts by weight of the metal oxide represented by the general formula .

Further,? And? Can satisfy 0.19 < 2.15? + 1.11? <1.

In the formula (1), x, y, and z may satisfy y + z? (11x / 14) - 0.037.

In addition, phase transition may not occur in a temperature range of -60 캜 to 100 캜.

On the other hand, in the piezoelectric element used for suppressing the cancer cell generation according to another embodiment of the present invention for realizing the above-described problems, the piezoelectric element is disposed at least in a part of the object where the cancer cells are generated, And the generation of the cancer cells is suppressed by using the vibration of the piezoelectric element, and the piezoelectric element can be composed of a mixture of an inorganic ferroelectric substance and a metal and an organic substance.

In addition, the inorganic ferroelectric material may include at least one of an oxide ferroelectric, a fluoride ferroelectric, a ferroelectric semiconductor, and a mixture of these inorganic materials.

In addition, the inorganic ferroelectric material may be PZT.

The organic material may be a polymeric ferroelectric material.

In addition, the polymer ferroelectric may be selected from the group consisting of polyvinylidene fluoride (PVDF), a polymer containing PVDF, a copolymer containing PVDF, a terpolymer containing PVDF, an odd number of nylons, a cyano polymer, Or the like.

Further, the ferroelectric substance can be used as a material of a ferroelectric transistor or a ferroelectric memory.

The piezoelectric element may further comprise: a main component containing a perovskite-type metal oxide represented by the following general formula (1); Mn as the first subcomponent; Li as the second subcomponent; And Bi as a third subcomponent, wherein the Mn content is 0.04 parts by weight or more and 0.36 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 wt% 0.0280 parts by weight or less, and the Bi content beta is 0.042 part by weight or more and 0.850 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the contents a and b are 0.5? (? MB) / 1 (wherein ML represents the atomic weight of Li, and MB represents the atomic weight of Bi).

&Lt; Formula 1 >

(Ba1-xCax) a (Ti1-y-zZrSnz) O3 wherein x, y, z and a are 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02 and 0.986? A? Lt; / RTI &gt;

Further, the fourth subcomponent further includes at least one of Si and B, wherein the content of the fourth subcomponent is 0.001 to 4.000 parts by weight, calculated as metal, based on 100 parts by weight of the metal oxide represented by the general formula .

Further,? And? Can satisfy 0.19 < 2.15? + 1.11? <1.

In the formula (1), x, y, and z may satisfy y + z? (11x / 14) - 0.037.

In addition, phase transition may not occur in a temperature range of -60 캜 to 100 캜.

According to another aspect of the present invention, there is provided a method for preventing cancer cell recurrence using a piezoelectric element, the method comprising: positioning a piezoelectric element on at least a part of an object for cancer cell removal surgery; Oscillating the piezoelectric element using an electrical signal derived from a human body; And preventing the removed arm from recurring by using the vibration of the piezoelectric element, wherein the piezoelectric element can be composed of a mixture of an inorganic ferroelectric material and a metal and an organic material.

The piezoelectric element may further comprise: a main component containing a perovskite-type metal oxide represented by the following general formula (1); Mn as the first subcomponent; Li as the second subcomponent; And Bi as a third subcomponent, wherein the Mn content is 0.04 parts by weight or more and 0.36 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 wt% 0.0280 parts by weight or less, and the Bi content beta is 0.042 part by weight or more and 0.850 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the contents a and b are 0.5? (? MB) / 1 (wherein ML represents the atomic weight of Li, and MB represents the atomic weight of Bi).

&Lt; Formula 1 >

(Ba1-xCax) a (Ti1-y-zZrSnz) O3 wherein x, y, z and a are 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02 and 0.986? A? Lt; / RTI &gt;

According to another aspect of the present invention, there is provided a method of inhibiting cancer cells using a piezoelectric element, the method comprising: positioning a first piezoelectric element on at least a part of an object where cancer cells are generated; Oscillating the first piezoelectric element using an electrical signal derived from a human body; And preventing an arm generated by using the vibration of the first piezoelectric element from being enlarged, wherein the piezoelectric element can be composed of a mixture of an inorganic ferroelectric material and a metal and an organic material.

The method may further comprise: surgically removing the cancer cells; Positioning the second piezoelectric element on at least a portion of the object after the cancer removal operation; Oscillating the second piezoelectric element using an electrical signal derived from the human body; And preventing the removed cancer cells from recurring by using the vibration of the second piezoelectric element.

The piezoelectric element may further comprise: a main component containing a perovskite-type metal oxide represented by the following general formula (1); Mn as the first subcomponent; Li as the second subcomponent; And Bi as a third subcomponent, wherein the Mn content is 0.04 parts by weight or more and 0.36 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 wt% 0.0280 parts by weight or less, and the Bi content beta is 0.042 part by weight or more and 0.850 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the contents a and b are 0.5? (? MB) / 1 (wherein ML represents the atomic weight of Li, and MB represents the atomic weight of Bi).

&Lt; Formula 1 >

(Ba1-xCax) a (Ti1-y-zZrSnz) O3 wherein x, y, z and a are 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02 and 0.986? A? Lt; / RTI &gt;

The present invention can provide a method and an apparatus for preventing and eliminating cancer cells using a piezoelectric device composed of an organic ferroelectric material. It should be understood, however, that the effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those skilled in the art to which the present invention belongs It will be possible.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to further the understanding of the technical idea of the invention, It should not be construed as limited.
1A and 1B show a specific example of a circulating tumor cell associated with the present invention.
2 shows a specific example of an antigen-antibody reaction between an EpCAM membrane protein that is highly expressed on the surface of CTC related to the present invention and an anti-EpCAM protein that selectively binds thereto.
3 is a schematic view showing a configuration of a piezoelectric element according to an embodiment of the present invention.
4A and 4B are cross-sectional schematic views showing the structure of a laminated piezoelectric element according to an embodiment of the present invention.
FIG. 5 is a flowchart for explaining a method of preventing occurrence of cancer again using a piezoelectric element after the cancer removal surgery proposed by the present invention.
FIG. 6 is a flowchart for explaining a method of preventing cancer from being enlarged proposed by the present invention, and preventing occurrence of cancer again after the cancer removal operation is performed using a piezoelectric element.
FIGS. 7A to 13 illustrate an example of a characteristic graph related to a capacitance characteristic according to a voltage of a ferroelectric substance according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention.

The same reference numerals are used for portions having similar functions and functions throughout the drawings. Throughout the specification, when a part is connected to another part, it includes not only a case where it is directly connected but also a case where the other part is indirectly connected with another part in between. In addition, the inclusion of an element does not exclude other elements, but may include other elements, unless specifically stated otherwise.

During chemotherapy, radiotherapy, or after treatment, and after surgery, there are some ties depending on the primary care physician or hospital, but generally the first three years after surgery are 3 to 6 months every 3 to 5 years every 6 months and 5 years after surgery In addition, there are some differences in the types of tests depending on the primary care physician or hospital. Usually blood tests such as general blood tests, liver function tests, tumor marker tests, etc. And simple chest radiography and abdominal computed tomography. The general blood test can be used as an indicator of whether or not you are getting good nutrition after surgery because you can see the presence of anemia and information. In addition, the number of leukocytes and the platelet count can be known, and it is possible to determine the degree of leukocyte reduction due to side effects of anticancer drugs and to know the degree and degree of inflammation when fever occurs.

Hepatic function tests can be used to assess hepatotoxicity and degree of hepatotoxicity following drug therapy and indirectly to assess nutritional status through changes in albumin levels after surgery. These tests are more effective than indirect tests , It is possible to evaluate overall health status by checking the body condition, but it is a limitation point in that it is not an examination for a specific reaction to cancer.

Some direct tests for tumors are as follows.

Tumor marker testing is a method that focuses on tumor markers such as cancerous fetal antigen (CEA), CA19-9, and the like that can be elevated in blood tests when cancer recurs.

There are some cases where it is affected by the ascending by other sides or by smoking, and if there is an abnormality, it does not mean recurrence.

In the case of simple chest X - ray examination, it is performed to find out whether lung metastasis is present. If abnormal findings are seen, CT scan is done and percutaneous needle aspiration biopsy is done.

Abdominal computed tomography (abdominal CT) is the most important diagnostic tool for the recurrence of localized recurrence, liver, and peritoneal recurrence. However, There has been a fundamental problem as far as possible.

In addition, in the examination of various cancer cells, there was also a problem that a small amount of tissue was not detected or detected.

In addition, the ability to perform complete tissue-state testing has yet to be tested. However, testing of cancer cells on a cell-by-cell basis has been deemed to be possible only a few years ago, but in recent years the presence of circulating tumor cells has led to cancer cell metastasis Has been reported to be a major cause of circulating tumor cells (CTC) that move away from cancerous tumors and travel in circulatory systems such as blood or bone marrow.

1A and 1B show a specific example of a circulating tumor cell associated with the present invention.

Referring to FIGS. 1A and 1B, a process of proliferating circulating tumor cells and a process of moving in blood are specifically shown.

Hereinafter, for convenience of explanation, a circulating tumor cell (CTC) is referred to as CTC.

Recently, a method for detecting circulating tumor cells (CTC) in blood has been proposed as a cancer metastasis diagnosis method.

This method utilizes the antigen-antibody reaction between the EpCAM membrane protein, which is highly expressed on the surface of CTC, and the anti-EpCAM protein, which selectively binds thereto, so that the analysis time is not long Respectively.

2 shows a specific example of an antigen-antibody reaction between an EpCAM membrane protein that is highly expressed on the surface of CTC related to the present invention and an anti-EpCAM protein that selectively binds thereto.

However, selective CTC separation is an essential process for subsequent analysis, since CTCs have different types of CTCs and different types of CTCs can identify the organs in which the cancer is present. And only CTC quantitative measurement is possible. Even if separation is performed, there are about 3 to 6 circulating tumor cells in about 1.5 L of ME blood, and these detection methods are rapidly emerging as the core contents of future studies have.

In 2008, the CTC detection chip was developed at MIT in the US, and Yu et al. Attempted to detect CTC through a biosensor array.

In the same year, Kiran et al. Attempted to apply gold nanoparticles and optical fibers. However, it has been found that the photoacoustics are different for each of a large number of known cancer cells.

Most of these methods have attempted to detect CTC from the blood by collecting a certain amount of blood, which is insufficient to detect a very small amount of blood CTC as described above.

Accordingly, the present invention proposes a method and apparatus for removing and preventing cancer cells using a piezoelectric element, which plays a crucial role in quickly and easily separating and detecting CTC.

Prior to detailed description of the present invention, a piezoelectric device applicable to the present invention will be described in detail.

The present invention relates to a lead-containing composition containing (Ba, Ca) (Ti, Zr, Sn) O3 as a main component, which has high density and high mechanical quality coefficient and does not undergo phase transition within an operating temperature range, -Free piezoelectric material.

These piezoelectric materials according to embodiments of the present invention have dielectric properties and can therefore be used in a variety of applications such as memory and sensors.

A piezoelectric material according to an embodiment of the present invention comprises: a main component containing a perovskite-type metal oxide represented by the following general formula (1); Mn as the first subcomponent; Li as the second subcomponent; And Bi as the third subcomponent, wherein the Mn content is 0.04 parts by weight or more and 0.36 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 wt% 0.0280 parts by weight or less, and the Bi content beta is 0.042 part by weight or more and 0.850 parts by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the contents a and b are 0.5? (? MB) / 1, wherein ML represents the atomic weight of Li, and MB represents the atomic weight of Bi.

&Lt; Formula 1 >

(Ba1-xCax) a (Ti1-y-zZrSnz) O3

 (Where x, y, z, and a satisfy 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02, and 0.986? A? 1.02)

The perovskite-type metal oxide represented by the general formula (1) is contained as a main component in the piezoelectric material.

The term "perovskite-type metal oxide" as used herein refers to perovskite-type metal oxides as described in the fifth edition of Iwanami Dictionary of Physics and Chemistry (published by Iwanami Shoten, Publishers., February 20, 1998) Structure (also referred to as a perovskite structure). In general, metal oxides having a perovskite type structure are represented by the formula ABO3. In the perovskite-type metal oxide, the elements A and B exist as ions and occupy specific positions (A-position and B-position) of the unit lattice. For example, in the case of a cubic unit lattice, the element A is located at the vertex of the cube, and the element B is located at the body center of the cube. The element O present as an oxygen anion occupies the face of the cube. In the above description, "the perovskite-type metal oxide represented by the formula (1) is contained as the main component" means that the main component for expressing the piezoelectric property is the perovskite-type metal oxide represented by the formula (1). For example, the piezoelectric material may contain a component for controlling the characteristics of the piezoelectric material, such as the manganese described above, or an impurity introduced during manufacture.

The piezoelectric material according to the embodiment of the present invention contains a perovskite-type metal oxide as a main phase from the standpoint of insulation. Whether or not the perovskite-type metal oxide constitutes the main phase can be determined, for example, as to whether or not the maximum diffraction intensity derived from the perovskite-type metal oxide is 100 times or more the maximum diffraction intensity derived from the impurity phase Can be determined based on the measurement of the piezoelectric material by X-ray diffraction measurement. When such a piezoelectric material is composed of a perovskite-type metal oxide alone, it has maximum insulation. The term "main phase" means that the piezoelectric material is measured by powder X-ray diffractometry and the peak with the highest diffraction intensity is derived from the perovskite type structure. The piezoelectric material may have a "single phase" structure, i.e., the piezoelectric material may be substantially entirely composed of perovskite type crystals.

In the metal oxide represented by the general formula (1), the metal element located at the A-position is Ba and Ca, and the metal element located at the B-position is Ti, Zr, and Sn. Some Ba and Ca ions may be located in the B-site. Similarly, some Ti and Zr ions may be located in the A-position. When the Sn ion is located at the A-site, the piezoelectricity may deteriorate.

In the formula (1), the molar ratio of the B-site element to the O element is 1: 3. However, the present invention also includes such a case that the molar ratio of these elements slightly deviates from 1: 3 (for example, in the range of 1.00: 2.94 to 1.00: 3.06) as long as the metal oxide has the perovskite type structure as the main phase.

The shape of the piezoelectric material according to the embodiment of the present invention is not limited, and may be any shape such as ceramic, powder, single crystal, film, or slurry. The piezoelectric material may have the form of a ceramic. As used herein, the term "ceramic" refers to aggregates (also referred to as bulk) of crystal grains, which are formed primarily of metal oxides and sintered by heat treatment, i.e., polycrystals. The term "ceramic" also refers to the polycrystalline processed after sintering.

In the formula (1), the Ca ratio x satisfies 0.09? X? 0.30. When the Ca ratio x is less than 0.09 and the Zr ratio y is not less than 0.025, the phase transition temperature (hereinafter referred to as Tto) from tetragonal to tetrahedral is more than -10 ° C. Tto can be reduced by adding Li and Bi components, but the addition of a large amount of Li and Bi is undesirable.

As the Zr ratio y and the Sn ratio z increase, Tto increases. However, as long as the Ca ratio x is 0.09 or more, the addition of Li and Bi components can reduce Tto to -30 占 폚 or less, regardless of the Zr ratio y and the Sn ratio z within the above range. If the ratio x is greater than 0.3, Ca will not dissolve into the solid at calcination temperatures below 1400 占 폚; CaTiO3, which serves as an impurity phase, is produced and the piezoelectric performance deteriorates. Therefore, the ratio x satisfies 0.09? X? 0.30 in order to reduce Tto to -10 占 폚 or less by the minimum addition of Li and Bi components and also to suppress the generation of CaTiO3 causing piezoelectric degradation. (BaTiO3 forms tetragonal at room temperature.) When BaTiO3 is cooled at room temperature, phase transition from Tto to quadrature occurs. When the BaTiO3 forming the orthorhombic crystal is heated, the phase transition from orthorhombic to tetragonal When the Ca ratio x is 0.12 or more, the addition of the Li and Bi components causes the phase transition temperature to decrease to -40 占 폚 or lower (hereinafter, referred to as &quot; Ta &quot; . As a result, the temperature dependence of the piezoelectricity within the operating temperature range can be reduced. In summary, the Ca ratio x preferably satisfies 0.12? X? 0.30.

The Zr ratio y satisfies 0.025? Y? 0.074. When the Zr ratio y is less than 0.025, the piezoelectricity decreases. When the Zr ratio y is more than 0.074, the Curie temperature (TC) may be less than 100 ° C. In order to achieve excellent piezoelectric properties and also to set TC to 100 DEG C or higher, y satisfies 0.025? Y? 0.074.

The Zr ratio y of 0.04 or more provides a high dielectric constant at room temperature, further increasing the piezoelectricity. Therefore, the Zr ratio y preferably satisfies 0.04? Y? 0.074.

Sn ratio z satisfies z? 0.02. Zr and Sn are added to increase the relative dielectric constant of the piezoelectric material. However, substituting Zr or Sn for Ti also increases the Tto of the piezoelectric material of the embodiment. Tto within the operating temperature range increases the temperature dependence of the piezoelectric performance, which is undesirable. Therefore, the increase of Tto due to the addition of Zr or Sn is canceled by the addition of Ca having the effect of decreasing Tto. The increase in Tto is lower when Ti is replaced with Sn compared to the case where Ti is replaced with Zr. In BaTiO3, substituting Zr for 1% Ti increases Tto by 12 ° C, and substituting 1% Ti for Sn increases Tto by 5 ° C. Therefore, substituting Ti with Sn requires a smaller amount of Ca. When the piezoelectric material has a low Ca content, it has a high mechanical quality factor. Therefore, the Sn ratio z is set to satisfy z? 0.02. If the ratio z satisfies z > 0.02, depending on the Zr ratio, the TC may be less than 100 DEG C, which is undesirable.

(Ba + Ca) / (Zr + Ti + Sn) of the total mole number of Ba and Ca with respect to the total mole number of Zr, Ti and Sn satisfies 0.986? A? 1.02. If the ratio a is less than 0.986, abnormal grain growth occurs during firing. The average particle size becomes 50 占 퐉 or more, and the mechanical strength and the electromechanical coupling coefficient of the material become low. When the ratio a is larger than 1.02, a piezoelectric material having a high density can not be obtained. A piezoelectric material having a low density has a low piezoelectric property. In an embodiment, a sample that is not sufficiently calcined has a density of 5% or more lower than a sufficiently calcined high-density sample.

In order to obtain a piezoelectric material having high density and high mechanical strength, the ratio a is set to satisfy 0.986? A? 1.02.

The piezoelectric material of the embodiment contains Mn as a first accessory ingredient. The Mn content is 0.04 part by weight or more and 0.36 part by weight or less based on 100 parts by weight of the perovskite-type metal oxide represented by the general formula (1). When the Mn content satisfies the above range, the mechanical quality factor increases. When the Mn content is less than 0.04 parts by weight, the effect of increasing the mechanical quality factor is not obtained. On the other hand, when the Mn content exceeds 0.36 parts by weight, the insulation resistance of the piezoelectric material decreases.

When the piezoelectric material has a low insulation resistance, an AC electric field having a frequency of 1 kHz and a field intensity of 10 V / cm at room temperature is applied and the dielectric loss tangent of the piezoelectric material measured by the impedance analyzer is more than 0.01 or the resistivity is 1 G? Or less.

Mn preferably occupies the B-site. Generally, Mn has a valence of 4+, 2+, or 3+. If there is a conduction atom in the crystal (e.g., when there is an oxygen defect in the crystal or the donor element occupies the A-site), a decrease in the valence of Mn from 4+ to 3+ or 2+ To increase the insulation resistance.

When Mn has a valence of less than 4+, such as 2+, Mn acts as a receptor. When Mn is present as a receptor in the perovskite structure crystal, holes are formed in the crystal or an oxygen vacancy is formed in the crystal.

When most of the added Mn ions have a valence of 2+ or 3+, the introduction of oxygen vacancies is sufficiently compensated, and the insulation resistance is reduced. Therefore, most Mn ions preferably have a valence of 4+. However, very few Mn ions have valencies of less than 4+, thus acting as receptors, occupying the B-site of the perovskite structure, and forming oxygen vacancies. This is because the Mn ion and the oxygen vacancy having 2+ or 3+ valences increase the mechanical quality factor of the piezoelectric material by forming a defective dipole. When the trivalent Bi ion occupies the A-site, the Mn ion tends to have a valence of less than 4+ to maintain balance in charge.

The valence of Mn added in very small amounts to a non-magnetic (semi-magnetic) material can be evaluated by measuring the temperature dependence of the susceptibility. The susceptibility can be measured by a superconducting quantum interference device (SQUID), a vibrating sample magnetometer (VSM), or a magnetic balance. Generally, the magnetic susceptibility x obtained by the measurement follows the Curie-Weiss law expressed by the following equation (2).

&Quot; (2) &quot;

? = C / (T -?)

Where C represents a Curie constant and? Represents a paramagnetic Curie temperature.

Generally, when a Mn added in a very small amount to a nonmagnetic material has a valence of 2+, it has a spin S of 5/2, and when Mn has a valence of 3+, it has a spin S of 2; If Mn has a valence of 4+, it has a spin S of 3/2. The Curie constant C converted to the Mn unit amount corresponds to the spin value S of Mn having the valence. Therefore, the valence of Mn can be evaluated by obtaining the Curie constant C from the temperature dependency of the susceptibility x.

For the evaluation of the Curie constant C, the temperature dependence of the susceptibility is preferably measured from as low as possible. This is because the amount of Mn is very small and therefore the measurement is difficult because of relatively high temperature, for example, a very low magnetic susceptibility near room temperature. The Curie constant C can be obtained in the following way: plotting the reciprocal of the susceptibility, 1 / x, against the temperature T and linearly approximating the plot; The slope of the generated line is determined as a Curie constant C.

The piezoelectric material of the embodiment contains Li as the second subcomponent and Bi as the third subcomponent. The Li content (?) With respect to 100 parts by weight of the perovskite-type metal oxide represented by the general formula (1) is 0.0013 parts by weight or more and 0.0280 parts by weight or less in terms of metals. The Bi content (?) With respect to 100 parts by weight of the perovskite-type metal oxide represented by the general formula (1) is 0.042 parts by weight or more and 0.850 parts by weight or less in terms of metals. The Li content? And the Bi content? Satisfy the relation of the following formula (1).

&Quot; (1) &quot;

0.5? (? MB) / (? ML)? 1

In the above formula, ML represents the atomic weight of Li, and MB represents the atomic weight of Bi.

When the Li content is less than 0.0013 parts by weight and the Bi content is less than 0.042 parts by weight, the effect of decreasing the phase transition temperature and increasing the mechanical quality factor is not obtained. When the Li content exceeds 0.0280 parts by weight and the Bi content exceeds 0.850 parts by weight, the electromechanical coupling coefficient decreases by more than 30% as compared with the case where Li and Bi are not added. When the Li-Bi molar ratio (alpha. MB) / (beta ML) is less than 0.5, the Curie temperature decreases, which is not preferable. When the Li-Bi molar ratio (? MB) / (? ML) is more than 1, the dielectric loss tangent increases. When Li and Bi are present to satisfy Equation (1), the Curie temperature does not decrease, the insulation resistance does not decrease, Tto and Tot can decrease, and the mechanical quality factor can increase.

Some of the added Li and Bi may be present in the grain boundaries or dissolved in the perovskite type structure of (Ba, Ca) (Ti, Zr, Sn) O3. Li and Bi are (Li0.5Bi0.5)

2+ and occupy the A-seat. Li and Bi serve as acceptors and can occupy 4-valent B-sites.

When Li and Bi are present in the grain boundaries, the intergranular friction decreases and the mechanical quality factor increases. When Li and Bi are dissolved in the perovskite structure of (Ba, Ca) (Ti, Zr, Sn) O3, Tot and Tto can be reduced and the mechanical quality factor can be further increased.

The positions of Li and Bi can be measured by, for example, X-ray diffraction measurement, electron beam diffraction measurement, electron microscopy, or laser ablation ICP-MS.

When Li and Bi occupy the B-site, the lattice constant of the perovskite structure increases because Li and Bi have a larger ion radius than Ti and Zr.

When Li and Bi occupy the A-site, the optimum value a is decreased to provide a high-density ceramic by firing.

In the BaO-TiO2 phase diagram, the TiO2-rich region for the composition having a molar ratio of BaO and TiO2 of 1: 1 has a liquid phase at high temperature. Thus, during the firing of BaTiO3 ceramics, when the TiO2 content exceeds the stoichiometric ratio, the liquid phase sintered causing abnormal grain growth. On the other hand, when the BaO content is high, the possibility of sintering is low and the produced ceramic has a low density. LiBiO2 is known as a sintering auxiliary, but Li and Bi components occupy the A-site, so that excessive A-site components are provided, and sintering of the ceramic can be suppressed. As a result, the produced ceramic has a low density. In this case, by decreasing the value a, sintering can be promoted and a high-density sample can be obtained.

The Li content, Bi content, and Li-Bi content ratios can be evaluated, for example, by ICP analysis.

5 mol% or less of Ba and Ca may be substituted with a divalent metal element such as Sr in order to facilitate the production of the piezoelectric material of the embodiment and adjust the characteristics of the piezoelectric material of the embodiment. Similarly, up to 5 mol% of Ti, Zr, and Sn can be replaced with a tetravalent metal element such as Hf.

The density of the sintered body can be measured, for example, by the Archimedes method. In the embodiment, when the ratio of the measured density (? Meas.) Of the sintered body to the theoretical density (? Calc.) Obtained from the lattice constant of the sintered body and the relative density (100? Calc ./rmeasas.) Is 95 or more, It is considered to have a sufficiently high density.

The Curie temperature TC is as follows: Piezoelectric material loses piezoelectricity above Curie temperature TC. In the present specification, the temperature at which the phase transition temperature is close to the phase transition temperature between the ferroelectric phase (tetragonal phase) and the phase dielectric phase (cubic phase) and the maximum permittivity is defined as TC. The permittivity is measured by an impedance analyzer, for example, by applying an alternating electric field having a frequency of 1 kHz and an electric field intensity of 10 V / cm.

As the temperature increases from low temperature, the piezoelectric material of the embodiment sequentially undergoes phase transition from quadratic, orthorhombic, tetragonal, cubic to hexagonal. The phase transition referred to herein refers to a phase transition from only tetragonal to tetragonal or from tetragonal to tetragonal. The phase transition temperature can be evaluated in the same manner as in the Curie temperature, and the temperature at which the maximum permittivity is defined as the phase transition temperature. The crystal system can be evaluated by, for example, X-ray diffraction measurement, electron beam diffraction measurement, or Raman spectroscopy.

One of the factors reducing the mechanical quality factor is the domain wall vibration. Generally, the more complex the domain structure, the higher the density of domain walls and the lower the mechanical quality factor. The crystal orientations of the spontaneous polarization of the orthorhombic perovskite structure and the tetragonal perovskite structure are respectively <110> and <100> in pseudo-cubic notation. That is, the spatial freedom of spontaneous polarization is lower in the tetragonal structure than in the orthogonal structure. Thus, the tetragonal structure has a simpler domain structure, and even in the case of the same composition, it has a higher mechanical quality factor. Thus, the piezoelectric material of the embodiment preferably has a tetragonal structure rather than a tetragonal structure within an operating temperature range.

At a temperature near the phase transition temperature, the dielectric constant and the electromechanical coupling coefficient become maximum, and the Young's modulus becomes minimum. The piezoelectric constant is a function of these three parameters, which have a maximum value or inflection point at a temperature near the phase transition temperature. Therefore, when a phase transition occurs within the operating temperature range of the device, the performance of the device is excessively changed corresponding to the temperature change, or the resonance frequency is changed corresponding to the temperature change, making it difficult to control the device. In summary, it is desirable that the phase transition, which is the greatest factor causing a change in the piezoelectric performance, does not occur within the operating temperature range. The farther the phase transition temperature is from the operating temperature range, the lower the temperature dependency of the piezoelectric performance within the operating temperature range, which is preferable.

The piezoelectric material of the embodiment may contain a fourth subcomponent including at least one of Si and B. [ The content of the fourth subcomponent may be 0.001 part by weight or more and 4.000 parts by weight or less based on 100 parts by weight of the metal oxide represented by the general formula (1). The fourth subcomponent has an effect of reducing the firing temperature of the piezoelectric material of the embodiment. When a piezoelectric material is used for a laminated piezoelectric element, the piezoelectric material is sintered together with the electrode material in the production process of the laminated piezoelectric element. Generally, the electrode material has a lower heat-resistant temperature than the piezoelectric material. Therefore, when the firing temperature for the piezoelectric material can be reduced, the energy required for the sintering decreases and the number of the electrode materials to be selected increases, which is preferable.

When the content of the fourth subcomponent is less than 0.001 part by weight, the effect of reducing the firing temperature is not provided. If the fourth subcomponent content is greater than 4.000 parts by weight, the sample does not contain the fourth subcomponent and is present in an amount of less than 30% relative to the sample obtained by firing under optimal conditions (e.g., air firing at 1300 ° C to 1350 ° C) Or more. When the content of the fourth subcomponent is 0.001 parts by weight or more and 4.000 parts by weight or less, the piezoelectricity reduction can be suppressed to less than 30%, and the firing temperature can be reduced. Particularly, when the content of the fourth subcomponent is 0.05 parts by weight or more, high-density ceramics can be provided by firing at a firing temperature of less than 1250 DEG C, which is more preferable. When the content of the fourth subcomponent is 0.09 part by weight or more and 0.15 part by weight or less, firing can be performed at 1200 캜 or less, and the piezoelectricity reduction can be suppressed to 20% or less, which is even more preferable.

In the piezoelectric material of the embodiment,? And? Can satisfy 0.19 < 2.15? + 1.11? <1. Compared to the case where? and? do not satisfy this relationship, when? and? satisfy this relationship, the piezoelectric material has a high mechanical quality factor.

The piezoelectric material of the embodiment can satisfy y + z? (11x / 14) - 0.037 in the formula (1). When x, y, and z satisfy this relationship, Tto is less than -20 占 폚.

The piezoelectric material of the embodiment preferably has no phase transition temperature in the range of -60 占 폚 to 100 占 폚. If the piezoelectric material does not have a phase transition temperature within the above range, the possibility of characteristic change at the operating temperature is low.

The method for producing the piezoelectric material of the embodiment is not particularly limited.

When piezoelectric ceramics are produced, standard sintering methods of solid powders containing, for example, oxides, carbonates, nitrates, and oxalates containing constituent elements at normal pressure can be used. These raw materials include metal compounds such as a Ba compound, a Ca compound, a Ti compound, a Zr compound, a Sn compound, a Mn compound, a Li compound, and a Bi compound.

Examples of usable Ba compounds include barium oxide, barium carbonate, barium oxalate, barium acetate, barium nitrate, barium titanate, barium zirconium, and barium zirconium zirconium titanate.

Examples of usable Ca compounds include calcium oxide, calcium carbonate, calcium oxalate, calcium acetate, calcium titanate, and calcium zirconate.

Examples of usable Ti compounds include titanium oxide, barium titanate, barium zirconium, and calcium titanate.

Examples of usable Zr compounds include zirconium oxide, barium zirconium oxide, barium zirconium zirconium titanate, and calcium zirconate.

Examples of usable Sn compounds include tin oxide, barium tartrate, and calcium stannate.

Examples of usable Mn compounds include manganese carbonate, manganese monoxide, manganese dioxide, trioxide manganese, and manganese acetate.

Examples of usable Li compounds include lithium carbonate and lithium bismuthate.

Examples of usable Bi compounds include bismuth oxide and lithium bismuthate.

The material used for adjusting the molar ratio a of the content of Ba and Ca in the A-site to the content of Ti, Zr, and Sn in the B-site in the piezoelectric ceramics of the embodiment is not particularly limited. The Ba compound, the Ca compound, the Ti compound, the Zr compound, and the Sn compound provide the same effect.

The granulating method of the raw material powder of the piezoelectric ceramics of the embodiment is not particularly limited. Examples of binders usable in granulation include PVA (polyvinyl alcohol), PVB (polyvinyl butyral), and acrylic resin. The amount of the binder to be added is preferably 1 part by weight to 10 parts by weight, more preferably 2 parts by weight to 5 parts by weight from the viewpoint of increasing the density of the molded article. The powder mixture obtained by mechanical mixing of Ba compound, Ca compound, Ti compound, Zr compound, Sn compound, and Mn compound can be granulated; These compounds can be calcined at about 800 ° C to about 1300 ° C and then granulated; Or a Ba compound, a Ca compound, a Ti compound, a Zr compound, a Sn compound, a Li compound, and a Bi compound can be sintered, and a Mn compound and a binder can be simultaneously added to these sintered compounds. The most preferred granulation method is the spray drying method because the particle size of the granulated powder can become more uniform.

The forming method of the piezoelectric ceramics of the embodiment is not particularly limited. The shaped body is a raw material powder, a granulated powder, or a solid formed from a slurry. The shaped body can be formed by, for example, uniaxial pressing, cold isostatic pressing, hot isostatic pressing, casting, or extrusion.

The sintering method of the piezoelectric ceramics of the embodiment is not particularly limited. The sintering can be performed by, for example, sintering by electric furnace, sintering by gas furnace, electric heating, microwave sintering, millimeter wave sintering, or HIP (hot isostatic pressing). Sintering by electric furnace and sintering by gas furnace can be carried out continuously or batchwise.

In the sintering method, the ceramic firing temperature is not particularly limited. The ceramic calcination temperature is preferably the temperature at which the compound reacts and crystals grow sufficiently. The firing temperature is preferably 1100 DEG C to 1550 DEG C, and more preferably 1100 DEG C to 1380 DEG C from the viewpoint of providing ceramic particles having a particle size of 3 mu m to 30 mu m. Piezoelectric ceramics obtained by sintering in this temperature range have excellent piezoelectric performance.

In order to stabilize the characteristics of the piezoelectric ceramics obtained by sintering with high reproducibility, the sintering can be performed at a constant temperature within the above range for 2 hours to 24 hours or less.

A sintering method such as a two-step sintering method may be used. However, from the viewpoint of productivity, a sintering method which does not involve a rapid temperature change can be used.

After polishing the piezoelectric ceramic, it can be heat-treated at a temperature of 1000 ° C or higher. When the piezoelectric ceramic is mechanically polished, residual stress is generated in the piezoelectric ceramic. By subjecting such a piezoelectric ceramic to a heat treatment at 1000 占 폚 or higher, the residual stress is reduced and piezoelectric properties of the piezoelectric ceramic are improved. This heat treatment also removes the raw powder such as barium carbonate deposited at the grain boundaries. The heat treatment time is not particularly limited and may be one hour or more.

If the piezoelectric material of the embodiment has a crystal grain size of greater than 100 占 퐉, the material may have insufficient strength for cutting and polishing. When the particle size is less than 0.3 탆, the piezoelectricity is reduced. In short, the particle size is preferably 0.3 mu m or more and 100 mu m or less, more preferably 3 mu m or more and 30 mu m or less on average.

The term "particle size" as used herein refers to the diameter of a complete circle having the same area as the projected area of the crystal grains, i.e., the " projected area circle equivalent diameter " In an embodiment, the method of measuring the particle size is not particularly limited. For example, the surface of the piezoelectric material is photographed with a polarizing microscope or a scanning electron microscope; The obtained micrograph is applied to image processing, and the particle size is measured. Since the optimum magnification depends on the target particle size, selection from an optical microscope and an electron microscope can be performed on the target particle size.

Instead of the image of the surface of the material, the circle equivalent diameter can be measured from the image of the abrasive surface or the cross section of the material.

When the piezoelectric material of the embodiment is used as a film to be formed on a substrate, the piezoelectric material preferably has a thickness of not less than 200 nm and not more than 10 mu m, more preferably not less than 300 nm and not more than 3 mu m. This is because a piezoelectric material having a film thickness of 200 nm or more and 10 m or less has sufficient electromechanical conversion function as a piezoelectric element.

The film forming method is not particularly limited. Examples of film forming methods include chemical solution deposition (CSD), sol-gel methods, metal organic chemical vapor deposition (MOCVD), sputtering methods, pulsed laser deposition (PLD), hydrothermal synthesis methods, and aerosol deposition (AD). Of course, the most preferred film forming methods are chemical solution deposition and sputtering. The chemical solution deposition or sputtering method enables easy formation of a film having a large area. The substrate used for the piezoelectric material of the embodiment is preferably a single crystal substrate provided by cutting and polishing along (001) plane or (110) plane. By using a monocrystalline substrate provided by cutting and polishing along a specific crystal plane, the piezoelectric material film formed on the substrate surface can be formed strongly oriented in the same direction as the substrate.

Hereinafter, a piezoelectric element including a piezoelectric material according to an embodiment of the present invention will be described.

3 is a schematic view showing a configuration of a piezoelectric element according to an embodiment of the present invention. The piezoelectric element of the embodiment includes at least a first electrode 1, a piezoelectric material 2, and a second electrode 3. The piezoelectric material 2 is a piezoelectric material according to an embodiment of the present invention.

In the case of forming the piezoelectric element including at least the first electrode and the second electrode using the piezoelectric material of the embodiment, the piezoelectric property of the piezoelectric material can be evaluated. The first and second electrodes are conductive layers each having a thickness of about 5 nm to about 2000 nm. The material of the electrode is not particularly limited, and may be selected from a material generally used for a piezoelectric element. Examples of the material include metals such as Ti, Pt, Ta, Ir, Sr, In, Sn, Au, Al, Fe, Cr, Ni, Pd, Ag and Cu and compounds of these metals.

The first electrode and the second electrode may be formed of a single material selected from the above examples. Alternatively, each electrode may be constituted by a lamination of two or more kinds of materials selected from the above examples. The first electrode may be formed of a material different from the material of the second electrode.

The method of forming the first electrode and the second electrode is not limited. The first electrode and the second electrode may be formed by, for example, baking, sputtering, or a deposition method of a metal paste. The first electrode and the second electrode may be patterned to have a desired shape and then used.

The piezoelectric element may have a polarization axis aligned in a specific direction. When the piezoelectric element has a polarization axis aligned in a specific direction, it has a high piezoelectric constant.

The polarization method of the piezoelectric element is not particularly limited. The polarization treatment can be carried out in air or in oil. The polarization temperature may be from 60 캜 to 130 캜, but the optimum conditions are somewhat different depending on the composition of the piezoelectric material constituting the piezoelectric element. The electric field applied to the material in the polarization treatment may have a strength equal to or larger than that of the coercive field of the material, specifically, 1 to 5 kV / mm.

The piezoelectric constant and the electromechanical quality factor of the piezoelectric element can be calculated based on the Japan Electronics and Information Technology Industries Consultation Standard (JEITA EM-4501) from the measurement results of the resonance frequency and the anti-resonance frequency obtained using a commercially available impedance analyzer have. Hereinafter, this method is referred to as a resonance-anti-resonance method.

Hereinafter, a laminated piezoelectric element including a piezoelectric material according to an embodiment of the present invention will be described.

[Laminated piezoelectric element]

A laminated piezoelectric element according to an embodiment of the present invention includes an electrode layer including a piezoelectric material layer and an internal electrode. The piezoelectric material layer and the electrode layer are alternately laminated. The piezoelectric material layer contains the piezoelectric material according to the embodiment of the present invention.

4A is a schematic cross-sectional view showing the structure of a laminated piezoelectric element according to an embodiment of the present invention. The laminated piezoelectric element of the embodiment includes an electrode layer including a piezoelectric material layer 54 and an internal electrode 55. The piezoelectric material layer and the electrode layer are alternately laminated. The piezoelectric material layer 54 is formed of the above-described piezoelectric material. The laminated piezoelectric element may include an external electrode such as the first electrode 51 and the second electrode 53 in addition to the internal electrode 55.

Fig. 4A shows a case where two layers of piezoelectric material 54 and one internal electrode 55 are alternately laminated; And this layered structure is sandwiched between the first electrode 51 and the second electrode 53. The laminated piezoelectric element shown in Fig. As shown in Fig. 4B, the number of piezoelectric material layers and the number of internal electrodes can be increased, and the number of laminated layers is not limited. 4B, the laminated piezoelectric element has the following configuration: nine layers of piezoelectric material layers 504 and eight layers of internal electrodes 505 are alternately laminated; This layered structure is sandwiched between the first electrode 501 and the second electrode 503; External electrodes 506a and 506b are provided for shorting the alternately formed internal electrodes.

The inner electrodes 55 and 505 and the outer electrodes 506a and 506b are not necessarily required to have the same size and shape as the piezoelectric material layers 54 and 504. [ The internal electrodes 55 and 505 and the external electrodes 506a and 506b may be divided into a plurality of parts.

The inner electrodes 55 and 505 and the outer electrodes 506a and 506b are each composed of a conductive layer having a thickness of about 5 nm to about 2000 nm. The material of these electrodes is not particularly limited, and can be selected from a material generally used for a piezoelectric element. Examples of the material include compounds of metals and metals such as Ti, Pt, Ta, Ir, Sr, In, Sn, Au, Al, Fe, Cr, Ni, Pd, Ag and Cu. The inner electrodes 55 and 505 and the outer electrodes 506a and 506b may be formed of a single material selected from the above examples or an alloy of two or more materials selected from the above examples. Alternatively, each electrode may be composed of a laminated layer of two or more materials selected from the above examples. The different electrodes may be formed of different materials. Since the electrode material is inexpensive, the internal electrodes 55 and 505 may include at least one of Ni and Cu. When the internal electrodes 55 and 505 are formed to include at least one of Ni and Cu, the laminated piezoelectric device of the embodiment can be fired in a reducing atmosphere.

In the laminated piezoelectric device according to the embodiment of the present invention, the internal electrode may contain Ag and Pd, and the weight ratio M1 / M2 of the Ag content M1 and the Pd content M2 may satisfy 0.25? M1 / M2? 4.0 . When the weight ratio M1 / M2 is less than 0.25, the firing temperature of the internal electrode increases, which is not preferable. On the other hand, when the weight ratio M1 / M2 is more than 4.0, the internal electrodes are formed in island pattern, that is, in a nonuniform configuration in the surface, which is not preferable. The weight ratio M1 / M2 is preferably 0.3? M1 / M2? 3.0.

As shown in Fig. 4B, a plurality of electrode layers including the internal electrode 505 can be short-circuited together for the purpose of forming an in-phase driving voltage. For example, a configuration in which the internal electrode 505, the first electrode 501, and the second electrode 503 are alternately short-circuited can be used. The configuration of the short circuit between the electrodes is not limited. It is possible to provide an electrode or wiring for short-circuiting on the side of the laminated piezoelectric element; Or a through-hole through the piezoelectric material layer 504, and a conductive material may be disposed in the through-hole to short the electrode.

On the other hand, a method for preventing cancellation and recurrence of cancer proposed by the present invention based on the above-described piezoelectric element will be described below.

In general, the discovery of cancer compares the basic weight of organs with the weights of the organs that have developed cancer, and judges that cancer has occurred if the mass is large.

On the other hand, with regard to cancer incidence, statistics show that there is little cancer incidence in the frequently moving organs.

In other words, cancer occurs frequently in organs with little exercise.

On the other hand, there is little cancer in many muscles with a lot of exercise.

Therefore, in the present invention, a method of minimizing the occurrence of cancer by moving an organ such as organs using the vibration of the piezoelectric element is proposed.

Particularly, the present invention proposes a method using electricity naturally induced in the human body in connection with an electric signal for driving a piezoelectric element.

Although the piezoelectric elements have been described above in the above description, the three suggestions in this specification can be applied through the piezoelectric film.

FIG. 5 is a flowchart for explaining a method of preventing occurrence of cancer again using a piezoelectric element after the cancer removal surgery proposed by the present invention.

Referring to FIG. 5, the step S110 of positioning the piezoelectric element in the region where the cancer removal operation is performed may be performed first.

Thereafter, the piezoelectric element may vibrate using an electrical signal derived from the human body (S120).

Materials and operating principles applicable to piezoelectric devices have been described above with reference to Figures 3 to 4B.

A step S130 of preventing the cancer from recurring using the vibration of the piezoelectric element may be performed.

According to another embodiment of the present invention, there is provided a method of preventing the cancer from spreading in a section where an arm has already been generated by using the vibration of the piezoelectric element.

That is, when vibration is applied to an organ in which cancer has already occurred, it is possible to prevent the cancer from becoming large. In the present invention, the vibration is to be generated by using the piezoelectric element.

FIG. 6 is a flowchart for explaining a method of preventing cancer from being enlarged proposed by the present invention, and preventing occurrence of cancer again after the cancer removal operation is performed using a piezoelectric element.

Referring to FIG. 6, the step S210 of placing the first piezoelectric element in a region where the arm is formed proceeds.

Next, a step S220 is performed in which the first piezoelectric element is vibrated using an electric signal derived from the human body.

Through step S220, the step S230 of preventing the arm from being enlarged by using the vibration of the first piezoelectric element is performed.

After the cancer removal operation, a second piezoelectric element (S240) described in FIG. 5 (S240), a step S250 of oscillating the second piezoelectric element using an electrical signal derived from the human body, and a step A step S260 of preventing cancer from recurring using vibration is performed.

Therefore, when the invention proposed by the present invention is applied, it is possible not only to prevent the cancer that has already occurred from being expanded, but also to prevent cancer from recurring in the organ after the cancer removal surgery.

While the present invention has been described with reference to the above-mentioned method, it is obvious that the present invention is not limited thereto and that the method can be provided to the patient through the apparatus.

Meanwhile, the piezoelectric device according to the present invention is composed of an organic ferroelectric material and can maximize its effect.

Hereinafter, this will be described in detail.

A variety of materials are currently known which exhibit ferroelectric properties. These materials are largely divided into inorganic and organic materials. Examples of the inorganic ferroelectric substance include an oxide ferroelectric substance, a fluoride ferroelectric substance such as BMF (BaMgF4), a ferroelectric semiconductor, and the like, and the organic ferroelectric substance is a polymeric ferroelectric substance.

Examples of the oxide ferroelectric material include perovskite ferroelectric materials such as PZT (PbZrxTi1-xO3), BaTiO3, and PbTiO3, pseudo-ilmenite ferroelectric materials such as LiNbO3 and LiTaO3, tungsten-bronze materials such as PbNb3O6 and Ba2NaNb5O15 (TB) ferroelectric, SBT (SrBi2Ta2O9), BLT ((Bi, La) 4Ti3O12), Bi4Ti3O12, and pyrochlore ferroelectrics such as La2Ti2O7, and solid solutions of these ferroelectrics, And Pb5Ge3O11, and BFO (BiFeO3), which contain rare earth elements (R) such as Y, Er, Ho, Tm, Yb and Lu.

Examples of the ferroelectric semiconductor include CdZnTe, CdZnS, CdZnSe, CdMnS, CdFeS, CdMnSe, and CdFeSe.

Examples of the polymeric ferroelectric material include polyvinylidene fluoride (PVDF), a polymer, a copolymer or a terpolymer containing the PVDF, and an odd number of nylon, a cyano polymer, Coalescence and so on.

In general, an inorganic ferroelectric such as an oxide ferroelectric, a fluoride ferroelectric, and a ferroelectric semiconductor has a much higher dielectric constant than an organic ferroelectric. Therefore, in the case of piezoelectric elements, superconducting elements, ferroelectric field effect transistors, ferroelectric memories, etc. which are generally proposed, an inorganic ferroelectric is employed as a material of the ferroelectric layer.

However, in the case of the inorganic ferroelectric substance described above, a high temperature treatment of, for example, 500 degrees or more is required when forming the inorganic ferroelectric substance on a substrate. Therefore, when the ferroelectric layer is formed on the silicon substrate, there arises a problem that elements such as Pb and Bi diffuse into the silicon substrate in the high-temperature process as described above.

On the other hand, in the case of the organic ferroelectric material, the formation temperature is very low, while the dielectric constant is lower than that of the inorganic ferroelectric material. Therefore, a ferroelectric material having a high dielectric constant and a low formation temperature is required.

Accordingly, the present inventors have studied a method of using a mixture of a ferroelectric inorganic material and a ferroelectric organic material as a ferroelectric material.

FIGS. 7A to 13 illustrate an example of a characteristic graph related to a capacitance characteristic according to a voltage of a ferroelectric substance according to the present invention.

For example, PZT (PbZrxTi1-xO3) and an organic ferroelectric material such as PVDFTrFE at a predetermined ratio to form a ferroelectric layer and measure the polarization characteristics thereof.

FIGS. 7A to 13 and FIGS. 7A to 7 show the mixing ratio of PZT and PVDF-TrFE to 1: 1, FIG. 8 shows a mixing ratio of PZT and PVDF-TrFE to 2: 1, 10 shows the polarization characteristics when the mixing ratio of PVDF-TrFE is 1: 2 and the mixing ratio of PVDF-TrFE is 1: 3.

7A, 8A, and 9A show that the thickness of the ferroelectric layer is 50 nm, and FIGS. 7B, 8B, 9B, 10, and 11 show the thickness of the ferroelectric layer of 75 nm, And the film thickness is 100 nm.

7 to 11, the formation temperature of the ferroelectric layer is shown to be 190 degrees, and the formation temperature of the ferroelectric layer is indicated by B in the case where the formation temperature of the ferroelectric layer is 170 degrees. Road.

In the ferroelectric material, the temperature for forming the ferroelectric layer is significantly lowered when the inorganic ferroelectric material and the organic ferroelectric material are mixed. However, as the organic material having a low dielectric constant is mixed with the inorganic material having a high dielectric constant, the overall dielectric constant of the ferroelectric material becomes lower than that of the conventional inorganic ferroelectric material.

Therefore, the above ferroelectric substance may not be suitable for application to a device requiring a high dielectric constant.

On the other hand, the present inventors have measured the properties of inorganic ferroelectric materials by mixing them with metals. According to the measurement results, it was confirmed that when the metal is mixed with the inorganic ferroelectric material, the spontaneous polarization value of the ferroelectric material varies depending on the kind of the metal and the mixing ratio thereof.

FIG. 12 is a graph showing polarization characteristics in the case where Fe, Cu and Al are mixed at a certain ratio with respect to PZT which is currently used as an inorganic ferroelectric material. FIG. And a residual polarization value (2Pr) of each mixed material.

FIGS. 12 and 13 show results obtained by mixing 1% by weight of a metal material with respect to PZT and forming a ferroelectric layer using the mixed material.

12 and 13, A is a graph showing the polarization characteristics of PZT, B is polarization characteristic of a material in which PZT is mixed with iron (Fe), C is polarization characteristic of a material in which PZT is mixed with copper (Cu) , And D is a graph showing the polarization characteristics of a material in which aluminum (Al) is mixed with PZT.

As can be seen from FIGS. 12 and 13, the ferroelectric material in which PZT is mixed with Fe has good hysteresis characteristics in accordance with a change in voltage as in the case of PZT, and exhibits a residual polarization value about twice or more as compared with PZT In case of ferroelectric material mixed with PZT and Cu or Al, it has good hysteresis characteristics according to the change of voltage like PZT, and exhibits a lower residual polarization value than PZT.

Accordingly, in the present invention, a ferroelectric material is used as a material in which a metal, an organic material, or an organic ferroelectric material is mixed with an inorganic ferroelectric material. In this case, the temperature for forming the ferroelectric layer is greatly lowered by the mixing of the organic material or the organic ferroelectric material, and the overall residual polarization value of the mixture, which is changed by mixing the organic material or the organic ferroelectric material, .

Herein, the following method can be used as a method of mixing the inorganic ferroelectric substance with the metal, organic substance or organic ferroelectric substance.

1. Mix inorganic and metallic and organic powders and dissolve them in solvent to create mixed solution.

2. Dissolve metal and organic powder in mineral solution to create mixed solution.

3. Dissolve metal and inorganic powders in organic solution to create mixed solution.

4. Mixture of mineral solution with metal solution and organic solution to form mixed solution.

Also, in the method of mixing the inorganic ferroelectric material with the metal and the organic material, it is possible to employ the following method.

1. Ferroelectric minerals and metals and organic materials.

2. Mix ferroelectric minerals and metals and ferroelectric organic matter.

3. Ferroelectric solid solution and mixed metal and organic matter.

4. Mix ferroelectric solid solution and metal and ferroelectric organic matter.

Of course, the mixing method and the method of mixing the inorganic material and the metal with the organic material are not limited to a specific one, and any arbitrary method capable of appropriately mixing the inorganic material and the organic material can be employed.

As the organic material mixed with the ferroelectric inorganic material and the metal, a general monomer, an oligomer, a polymer, a copolymer, and an organic material having a high dielectric constant may be used.

These materials include, for example, polyvinyl pyrrolidone (PVP), polycarbonate (PC), polyvinyl chloride (PVC), polystyrene (PS), epoxy, polymethyl methacrylate (PMMA), polyimide polyvinyl alcohol, nylon 66, and polyketone ketone (PEKK).

Examples of the organic material include fluorinated para-xylene, fluoropolyarylether, fluorinated polyimide, polystyrene, poly (? - methylstyrene) poly (vinyltoluene), polyethylene, cis-polybutadiene, poly (vinylidene fluoride), poly (vinylidene fluoride) Polypropylene, polyisoprene, poly (4-methyl-1-pentene), poly (tetrafluoroethylene), poly (Chlorotrifluoroethylene), poly (2-methyl-1,3-butadiene), poly (p-xylylene) p-xylylene), poly (? -? -? '-?' - tetrafluorop-xylylene), poly [ , 1- (2-methylpropane) bis (4-phenyl) carbonate] (poly [1,1- 2-methyl propane) bis (4-phenyl) carbonate], poly (cyclohexyl methacrylate), poly (chlorostyrene) Poly (2,6-dimethyl-1,4-phenylene ether), polyisobutylene, poly (vinyl cyclohexane), poly (Ethylene / tetrafluoroethylene), poly (ethylene / tetrafluoroethylene), poly (ethylene / chlorotrifluoroethylene), poly (arylene ether) and polyphenylene, (Ethylene / chlorotrifluoroethylene), fluorinated ethylene / propylene copolymer, polystyrene-co-a-methyl styrene, ethylene / ethyl acrylate (Ethylene / ethyl acrylate copolymer), poly (styrene / 10% butadiene), poly (styrene / 15% butadiene) (poly poly (styrene / 2,4-dimethylstyrene), Cytop, Teflon AF, polypropyleneco-1-butene, And the like may be used.

In addition, other conjugated hydrocarbon polymers such as polyacene, polyphenylene, poly (phenylene vinylene), and polyfluorene, and oligomers of such conjugated hydrocarbons ; Condensed aromatic hydrocarbons such as anthracene, tetracene, chrysene, pentacene, pyrene, perylene, and coronene; oligomeric para-substitution such as p-quaterphenyl (p-4P), p-quinquephenyl (p-5P), p-sexiphenyl Oligomeric para substituted phenylenes; Poly (3-substituted thiophene), poly (3,4-bisubstituted thiophene), polybenzothiophene), poly But are not limited to, polyisothianaphthene, poly (N-substituted pyrrole), poly (3-substituted pyrrole), poly (3,4- poly (3,4-bisubstituted pyrrole), polyfuran, polypyridine, poly-1,3,4-oxadiazoles, Poly (2-substituted aniline), poly (3-substituted aniline) (poly (N-substituted aniline) (3-substituted aniline), poly (2,3-bisubstituted aniline), polyazulene, polypyrene, and the like; Pyrazoline compounds; Polyselenophene; Polybenzofuran; Polyindole; Polypyridazine; Substituted metal-or-metal-free porphines, phthalocyanines, fluorophthalocyanines, naphthalocyanines or fluoronaphthalocyanines; C60 and C70 fullerenes; Substituted dialkyl, diaryl or substituted diaryl-1,4,5,8-naphthalenetetracarboxylic diimide (N, N'-dialkyl, substituted ialkyl, diaryl or substituted diaryl-1,4,5,8-naphthalenetetracarboxylic diimide) and fluorinated derivatives thereof; N, N'-dialkyl, substituted dialkyl, diaryl or substituted diaryl 3,4,9,10-perylene tetracarboxylic diimide (N, N'-dialkyl, substituted dialkyl, diaryl or substituted diaryl 3,4,9,10-perylenetetracarboxylic diimide); Bathophenanthroline; Diphenoquinones; 1,3,4-oxadiazoles; 11,11,12,12-tetracyanonaptho-2,6-quinodimethane; α, α'-bis (dithieno [3,2-b2 ', 3'-d] thiophene) ); Dialkyl, substituted dialkyl, diaryl or substituted diaryl anthradithiophene); a substituted or unsubstituted dialkyl, substituted or unsubstituted dialkyl; Bibenzo [1,2-b: 4,5-b '] dithiophene) and the like, Semi-conducting materials, compounds thereof, oligomers and compound derivatives, and the like can be used.

In the above-described method, the mixing ratio of the metal and the organic material to the inorganic material can be appropriately set as needed. If the mixing ratio of the organic material is increased, the permittivity of the mixture is lowered while the formation temperature is lowered. When the mixing ratio of the organic material is lowered, the permittivity of the mixture is increased while the formation temperature is higher.

The ferroelectric material according to the present invention has the following characteristics.

1. Since a ferroelectric layer is formed using a mixed solution of an inorganic material and a metal and an organic material, the ferroelectric layer can be easily formed using inkjet, spin coating, screen printing or the like.

2. Since the formation temperature of the ferroelectric layer is lowered, a ferroelectric layer having excellent data retention characteristics can be formed on the silicon substrate.

3. Since the formation temperature of the ferroelectric layer is lowered, piezoelectric elements, superconducting elements, field effect transistors, and ferroelectric memories can be formed on various types of substrates such as organic materials and paper instead of conventional silicon substrates.

Since the ferroelectric material according to the present invention has a low formation temperature, it is possible to use an organic material such as paper, paper coated with a coding material such as parylene or flexible plastic, as well as conventional Si and Ge wafers as a substrate have. Examples of organic materials that can be used at this time include polyimide (PI), polycarbonate (PC), polyethersulfone (PES), polyetheretherketone (PEEK), polybutylene terephthalate (PBT), polyethylene terephthalate (PE), ethylene copolymer, polypropylene (PP), propylene copolymer, poly (4-methyl-1-pentene) (TPX), polyarylate (PAR), polyacetal (POM), polyphenylene oxide (PPO), polysulfone (PSF), polyphenylene sulfide (PPS), polyvinylidene chloride (PVDC), polyvinyl acetate (PVAC), polyvinyl alcohol (PM), a fluororesin, a phenol resin (PF), a melamine resin (MF), a urea resin (UF), an unsaturated polyester (UP), an epoxy resin (EP), diallyl phthalate resin (DAP), polyurethane (PUR), polyamide (PA), silicone resin (SI) The can be used.

As described above, since the conventional inorganic ferroelectric material has a high formation temperature, various problems occur when the inorganic ferroelectric material is formed on a silicon substrate. On the other hand, in the case of the mixed material of the inorganic ferroelectric material and the metal and the organic material according to the present invention, it can be formed at a low temperature of, for example, 200 degrees or less.

Further, since the mixed solution of the inorganic ferroelectric material and the metal and the organic material can be formed by inkjet, spin coating, screen printing or the like, the ferroelectric layer can be formed to a thickness of 1 탆 or less, for example. When the thickness of the ferroelectric layer becomes thin, the voltage for polarizing the ferroelectric layer becomes very low. This means that the use of the ferroelectric material according to the present invention makes it possible to fabricate electronic and electric devices capable of operating at a very low voltage.

The piezoelectric element proposed by the present invention can be manufactured by the above-described organic ferroelectric substance.

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers of the technical field to which the present invention belongs.

It should be noted that the above-described apparatus and method are not limited to the configurations and methods of the embodiments described above, but the embodiments may be modified so that all or some of the embodiments are selectively combined .

Claims (27)

In a piezoelectric element used for preventing recurrence of cancer cells,
The piezoelectric element is located at least in a part of the object that has undergone cancer cell removal surgery, and vibrates using an electric signal derived from a human body.
The removed arm is prevented from recurring by using the vibration,
Wherein the piezoelectric element is composed of a mixture of an inorganic ferroelectric material and a metal and an organic material. The method according to claim 1,
Wherein the inorganic ferroelectric material includes at least one of an oxide ferroelectric, a fluoride ferroelectric, a ferroelectric semiconductor, and a mixture of these inorganic materials. The method according to claim 1,
Wherein the inorganic ferroelectric material is PZT. The method according to claim 1,
Wherein the organic material is a polymeric ferroelectric material. 5. The method of claim 4,
Wherein the polymeric ferroelectric is selected from the group consisting of polyvinylidene fluoride (PVDF), a polymer comprising PVDF, a copolymer comprising PVDF, a terpolymer comprising PVDF, an odd number of nylons, a cyano polymer and polymers or copolymers thereof And at least one piezoelectric element. The method according to claim 1,
Wherein the ferroelectric material is used as a material of a ferroelectric transistor or a ferroelectric memory. The method according to claim 1,
The piezoelectric element includes:
A main component containing a perovskite-type metal oxide represented by the following formula (1);
Mn as the first subcomponent;
Li as the second subcomponent; And
Bi as the third subcomponent,
The Mn content is 0.04 part by weight or more and 0.36 part by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 part by weight or more and 0.0280 parts by weight or less based on 100 parts by weight of the metal oxide, beta is not less than 0.042 part by weight and not more than 0.850 part by weight in terms of metal with respect to 100 parts by weight of the metal oxide and the contents of alpha and beta are 0.5? (? MB) / (? ML)? 1 , And MB represents the atomic weight of Bi).
&Lt; Formula 1 >
(Ba1-xCax) a (Ti1-y-zZrSnz) O3
(Where x, y, z, and a satisfy 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02, and 0.986? A? 1.02) 8. The method of claim 7,
Si, and B, wherein the content of the fourth subcomponent is 0.001 to 4.000 parts by weight, calculated as metal, based on 100 parts by weight of the metal oxide represented by the general formula (1) . 9. The method according to claim 7 or 8,
and? and? satisfy 0.19 < 2.15? + 1.11? <1. 9. The method according to claim 7 or 8,
Wherein x, y, and z in the formula (1) satisfy y + z? (11x / 14) - 0.037. 9. The method according to claim 7 or 8,
And the phase transition does not occur in a temperature range of -60 deg. C to 100 deg. In a piezoelectric element used for inhibiting the generation of cancer cells
The piezoelectric element is located at least a part of an object where the cancer cells are generated, and vibrates using an electric signal induced in the human body,
Generation of the cancer cells is suppressed by using the vibration of the piezoelectric element,
Wherein the piezoelectric element is composed of a mixture of an inorganic ferroelectric material and a metal and an organic material. 13. The method of claim 12,
Wherein the inorganic ferroelectric material includes at least one of an oxide ferroelectric, a fluoride ferroelectric, a ferroelectric semiconductor, and a mixture of these inorganic materials. 13. The method of claim 12,
Wherein the inorganic ferroelectric material is PZT. 13. The method of claim 12,
Wherein the organic material is a polymeric ferroelectric material. 16. The method of claim 15,
Wherein the polymeric ferroelectric is selected from the group consisting of polyvinylidene fluoride (PVDF), a polymer comprising PVDF, a copolymer comprising PVDF, a terpolymer comprising PVDF, an odd number of nylons, a cyano polymer and polymers or copolymers thereof And at least one piezoelectric element. 13. The method of claim 12,
Wherein the ferroelectric material is used as a material of a ferroelectric transistor or a ferroelectric memory. 13. The method of claim 12,
The piezoelectric element includes:
A main component containing a perovskite-type metal oxide represented by the following formula (1);
Mn as the first subcomponent;
Li as the second subcomponent; And
Bi as the third subcomponent,
The Mn content is 0.04 part by weight or more and 0.36 part by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 part by weight or more and 0.0280 parts by weight or less based on 100 parts by weight of the metal oxide, beta is not less than 0.042 part by weight and not more than 0.850 part by weight in terms of metal with respect to 100 parts by weight of the metal oxide and the contents of alpha and beta are 0.5? (? MB) / (? ML)? 1 , And MB represents the atomic weight of Bi).
&Lt; Formula 1 >
(Ba1-xCax) a (Ti1-y-zZrSnz) O3
(Where x, y, z, and a satisfy 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02, and 0.986? A? 1.02) 14. The method of claim 13,
Si, and B, wherein the content of the fourth subcomponent is 0.001 to 4.000 parts by weight, calculated as metal, based on 100 parts by weight of the metal oxide represented by the general formula (1) . The method according to claim 13 or 14,
and? and? satisfy 0.19 < 2.15? + 1.11? <1. The method according to claim 13 or 14,
Wherein x, y, and z in the formula (1) satisfy y + z? (11x / 14) - 0.037. The method according to claim 13 or 14,
And the phase transition does not occur in a temperature range of -60 deg. C to 100 deg. Positioning the piezoelectric element in at least a portion of the cancerous object removal surgery;
Oscillating the piezoelectric element using an electrical signal derived from a human body; And
Using the vibration of the piezoelectric element to prevent the removed arm from recurring,
Wherein the piezoelectric element is composed of a mixture of an inorganic ferroelectric material and a metal and an organic material. 24. The method of claim 23,
The piezoelectric element includes:
A main component containing a perovskite-type metal oxide represented by the following formula (1);
Mn as the first subcomponent;
Li as the second subcomponent; And
Bi as the third subcomponent,
The Mn content is 0.04 part by weight or more and 0.36 part by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 part by weight or more and 0.0280 parts by weight or less based on 100 parts by weight of the metal oxide, beta is not less than 0.042 part by weight and not more than 0.850 part by weight in terms of metal with respect to 100 parts by weight of the metal oxide and the contents of alpha and beta are 0.5? (? MB) / (? ML)? 1 And MB represents the atomic weight of Bi). &Lt; / RTI >
&Lt; Formula 1 &gt;
(Ba1-xCax) a (Ti1-y-zZrSnz) O3
(Where x, y, z, and a satisfy 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02, and 0.986? A? 1.02) Positioning the first piezoelectric element on at least a part of the object where the cancer cells occur;
Oscillating the first piezoelectric element using an electrical signal derived from a human body; And
And preventing the arm generated by using the vibration of the first piezoelectric element from becoming larger,
Wherein the piezoelectric element is composed of a mixture of an inorganic ferroelectric material and a metal and an organic material. 26. The method of claim 25,
Surgically removing the cancer cells;
Positioning the second piezoelectric element on at least a portion of the object after the cancer removal operation;
Oscillating the second piezoelectric element using an electrical signal derived from the human body; And
And preventing the removed cancer cells from recurring by using the vibration of the second piezoelectric element. 26. The method of claim 25,
The piezoelectric element includes:
A main component containing a perovskite-type metal oxide represented by the following formula (1);
Mn as the first subcomponent;
Li as the second subcomponent; And
Bi as the third subcomponent,
The Mn content is 0.04 part by weight or more and 0.36 part by weight or less in terms of metal based on 100 parts by weight of the metal oxide, and the Li content? Is 0.0013 part by weight or more and 0.0280 parts by weight or less based on 100 parts by weight of the metal oxide, beta is not less than 0.042 part by weight and not more than 0.850 part by weight in terms of metal with respect to 100 parts by weight of the metal oxide and the contents of alpha and beta are 0.5? (? MB) / (? ML)? 1 And MB represents the atomic weight of Bi). &Lt; / RTI >
&Lt; Formula 1 &gt;
(Ba1-xCax) a (Ti1-y-zZrSnz) O3
(Where x, y, z, and a satisfy 0.09? X? 0.30, 0.025? Y? 0.074, 0? Z? 0.02, and 0.986? A? 1.02)

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