KR101368330B1 - Highly dense magnetoelectric nanocomposite thick film and preparation method thereof - Google Patents

Abstract

The present invention relates to a high-density self-electrically bonded nanocomposite thick film and a method for manufacturing the same. Specifically, a ceramic material made of a mixed powder of piezoelectric ceramics and magnetostrictive ceramics is formed on a surface of a substrate at room temperature. Piezoelectric ceramics-magnetrons ceramic self-electrobonding nanocomposite thick films of 3-2 structure in which magnetostrictive ceramic phases are dispersed in 2D connectivity in a piezoelectric ceramic matrix by vacuum deposition by vacuum or AD; It is about. According to the present invention, using room temperature powder spray in vacuum (AD) or aerosol-deposition (AD), ferroelectricity and magnetic properties at the same time, dense film with high density, without cracking or pore formation In the electronic products, which are adhered to the substrate to a thickness of 5 μm or more without being separated from the substrate, and have a high density 3-2 nanocomposite thick film having a high self-electric coupling coefficient. Applications include thin film / thick film sensors, transducers, energy harvesting devices, electromagnetic shielding coatings, and the like.

Magnetoelectric nanocomposite thick film, piezoelectric, magnetostrictive, room temperature vacuum powder spraying, AD

Description

High density dense magnetoelectric nanocomposite thick film and preparation method

The present invention relates to a high density self-electrobonding nanocomposite thick film and a method of manufacturing the same.

The magnetoelectric effect (ME effect) is a property of the material and is widely found in composite structures made of magnetotrictive and piezoelectric materials. In these composites, the magnitude of the self-electrobonding effect depends on the elastic coupling occurring at the boundaries of the piezoelectric and magnetostrictive material phases.

Magnetic-electro-coupled materials with high coupling effects have been applied to thin film / thick film sensors, transducers, energy harvesting devices, electromagnetic shielding coatings, and the like.

Recently, it has been reported that electro-magnetic nanocomposite thin films of ferroelectric and magnetotrictive materials have been produced by pulsed laser deposition (PLD) and chemical solution deposition (CSD). However, it has been shown that 1-3 vertical heterostructures in which ferrimagnetic spinel phases are inserted in the form of a main phase in a ferroelectric matrix lack self-electric coupling properties even if they are continuous at the boundary.

On the other hand, 3-0 structures and 2-2 horizontal heterostructures were found to exhibit self-electric coupling properties. However, most of the self-electrobonding nanocomposite films reported in the literature have overall thickness due to strain created due to differences due to thermal inadequate coupling between the respective phases and the substrate. There was a problem that is limited.

In order to solve the above problems, the inventors of the present invention have fabricated a high density 3-2 nanocomposite thick film containing a ferroelectric material and a magnetostrictive material phase using a room temperature vacuum powder spraying method, and completed the present invention.

An object of the present invention is to provide a self-electrically bonded nanocomposite thick film composed of high-density piezoelectric ceramics and magnetostrictive ceramics.

It is another object of the present invention to provide a method for producing a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

Still another object of the present invention is to provide a sensor using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

Another object of the present invention is to provide a transducer using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

Still another object of the present invention is to provide an energy harvesting apparatus using the self-electrically bonded nanocomposite thick film formed of the piezoelectric ceramics and magnetostrictive ceramics.

It is another object of the present invention to provide an electromagnetic shielding coating using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

In order to achieve the above object, the present invention provides a self-electrically bonded nanocomposite thick film composed of high-density piezoelectric ceramics and magnetostrictive ceramics.

In addition, the present invention provides a method for producing a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and the magnetostrictive ceramics using a vacuum vacuum powder spraying method.

Furthermore, the present invention provides a sensor using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

In addition, the present invention provides a transducer using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

Furthermore, the present invention provides an energy harvesting apparatus using the self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

In addition, the present invention provides an electromagnetic wave shielding coating using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

According to the present invention, using a room temperature powder spray in vacuum (AD, aerosol-deposition) has a ferroelectric and magnetic properties, dense film is formed at high density, there is no crack or pore formation, Thin films in electronic products, which are adhered to the substrates with a thickness of 5 μm or more without any separation with the substrates and have a high density of 3-2 nanocomposite thick films having a high self-electric coupling coefficient, which are in the trend of light and thin shortening. Applications include thick-film sensors, transducers, energy harvesting devices and electromagnetic shielding coatings.

Hereinafter, the present invention will be described in detail.

The present invention provides a self-electrically bonded nanocomposite thick film in which a ceramic material is vacuum deposited on a surface of a substrate by room temperature powder spray in vacuum (AD) or aerosol-deposition (AD).

The self-electrobonding nanocomposite thick film is anchored on the outer surface of the substrate, characterized in that it has an adhesive force.

The self-electrobonding nanocomposite thick film has a thickness of 5 μm or more.

The structure of the self-electrically bonded nanocomposite thick film is composed of 3-2 piezoelectric ceramics and magnetostrictive ceramics in which the magnetostrictive ceramic phase is dispersed in 2D connectivity in the piezoelectric ceramic matrix.

The self-electrobonding nanocomposite thick film may contain 60 to 95 wt% of the piezoelectric ceramics and 5 to 40 wt% of the magnetostrictive ceramics.

The dielectric constant (ε _r ) of the self-electrobonding nanocomposite thick film is characterized in that it has a 200 ~ 250.

The self-electric coupling output voltage coefficient of the self-electrobonding nanocomposite thick film is characterized in that more than 100 mV / cm.Oe.

The self-electrobonding nanocomposite thick film is characterized in that it is possible to finely control the content by varying the composition.

Hereinafter, the structure of the self-electrobonding nanocomposite thick film forming apparatus for manufacturing the self-electrobonding nanocomposite thick film as described above will be described with reference to FIGS . 1 and 2 .

1 is a conceptual diagram showing the deposition principle of a self-electrobonding nanocomposite thick film according to the present invention, Figure 2 is a self-electrobonding nanocomposite thick film for producing a self-electrobonding nanocomposite thick film according to the present invention A schematic diagram showing the configuration of the forming apparatus is shown.

As shown in the drawing, the self-electrically bonded nanocomposite thick film forming apparatus 100 sprays and ceramics a ceramic material C on the substrate 240 by room temperature powder spray in vacuum. A device for forming the nanocomposite thick film 220.

Specifically, the self-electrically coupled nanocomposite thick film forming apparatus 100 includes a vacuum chamber 110 having a stage 112 moving in a state in which a substrate 240 is supported, and the vacuum chamber 110. The vacuum pump 120 to communicate with each other to form a vacuum in the vacuum chamber 110, the mixing vessel 130, the ceramic material (C) is accommodated, and the gas supply means 140, the carrier gas is stored and sprayed; A gas supply pipe 150 communicating with the gas supply means 140 and the inside of the mixing container 130 to guide the carrier gas into the mixing container 130, and a ceramic material mixed with the carrier gas. ) Is provided at one end of the transfer tube 160 to guide the inside of the vacuum chamber 110 and the transfer tube 160 to spray the ceramic material C via the transfer tube 160 to the substrate 240. It is configured to include a nozzle (170).

The stage 112 is fixed to the lower surface of the substrate 240, is configured to be movable in the three-axis direction, is moved at a speed of approximately 0.1 ~ 50 mm / sec. Therefore, when the ceramic material C is injected from the lower side of the substrate 240, the ceramic material C is anchored to the lower surface of the substrate 240 to form a self-electrically bonded nanocomposite thick film 220. The feed rate of the stage 112 may be variously applied to control the film formation rate and the surface roughness of the thick film of the self-electrobonding nanocomposite.

The vacuum chamber 110 forms a closed space and communicates with the vacuum pump 120 to become a vacuum state when the vacuum pump 120 operates, and the vacuum degree of the vacuum chamber 110 is 1 torr or less. Be sure to

The nozzle 170 is provided at a position spaced downward from the stage 112. The nozzle 170 is fixed at a predetermined position in the vacuum chamber 110 to guide the spraying direction of the ceramic material C and accelerate the powder mixed with the transport gas.

Therefore, when the ceramic material C is sprayed upward through the nozzle 170 and the substrate 240 is moved by the movement of the stage 112, the lower surface of the stage 112 may be According to the direction of movement, it is possible to form the magnetic-electrocoupled nanocomposite thick film 220 of various shapes.

The nozzle 170 is located at the lower end spaced apart from the substrate 240 by a distance of about 1 ~ 40 mm, in the embodiment of the present invention to be spaced about 5 mm.

And, the width of the nozzle 170 is to be 0.1 ~ 2.0 mm, the length of the nozzle 170 is to be 5 ~ 300 mm. The cross-sectional shape, width and length of the nozzle 170 may be variously changed and applied depending on the components of the ceramic material (C) and the deposition thickness of the self-electrically bonded nanocomposite thick film 220.

The nozzle 170 is in communication with the transfer pipe 160. The transfer tube 160 is to allow the ceramic material (C) inside the mixing vessel 130 to be guided to the nozzle 170 together with a carrier gas, both ends of the transfer tube 160 to the mixing vessel 130 And nozzles 170, respectively.

More specifically, the upper right end of the transfer pipe 160 is connected to the nozzle 170, and the lower left end is fixed to be positioned above the inside of the mixing container 130 so as not to contact the ceramic material C. .

The mixing container 130 receives the carrier gas through the gas supply pipe 150, disperses the ceramic material C contained therein, and simultaneously guides the ceramic material C and the carrier gas to the transfer pipe 160. It plays a role. The mixing container 130 may maximize dispersion of the ceramic material C by applying vibration.

To this end, the gas supply pipe 150 is located on the inner left side of the mixing vessel 130, the end of the gas supply pipe 150 is coupled in contact with the ceramic material (C) contained in the mixing vessel 130 do. The shape and structure of the mixing vessel 130 can be variously applied according to the structure of the equipment.

In addition, the ceramic material (C) is a mixed powder of piezoelectric ceramics and magnetostrictive ceramics is applied, wherein the piezoelectric ceramics and magnetostrictive ceramics may be used ceramics commonly used in the art. For example, in the piezoelectric ceramic is Pb (Zr, Ti) O _3, BaTiO _3, SrBi ₄ Ti ₄ O _12, (K _{0 .5 0 .5} Na) NbO _3, PZT, PNN-PZT, PZN-PT , PZN-PZT, and the like PZT-PMnN, PZNT, in the magnetostrictive ceramics are _{MnFe 2 O 4, Fe 3 O} 4, CoFe 2 O 4, MgFe 2 O 4, Li 0 .5 Fe 2 O 4, NiFe ₂ O ₄ , CuFe ₂ O ₄ , YFe ₂ O ₄ , SmFe ₅ O ₁₂ , DyFe ₅ O ₁₂ , EuFe ₅ O ₁₂ Ferrite-based ceramics having a spinel structure or the like or magnetic ceramics having a modified composition thereof (eg, NCZF) may be used, but are not limited thereto.

In order to obtain excellent properties of the magnetic-electric coupling composite, the piezoelectric voltage coefficient of the piezoelectric ceramics should be excellent, and the magnetostrictive properties of the magnetostrictive ceramics should be excellent. Thus, 0.8Pb having excellent piezoelectric voltmeter number and energy density in the present invention as one example of the ceramic material _{(Zr 0 .52 Ti 0 .48)} O 3 -0.2Pb (Zn 1/3 Nb 2/3) O 3 [ PZNT] a powder mixture of _{(Ni 0 .6 Cu 0 .2 Zn} 0 .2) Fe 2 O 4 [NCZF] was used having a ceramic and high magnetostrictive properties.

Next, the carrier gas introduced into the mixing vessel 130 through the gas supply pipe 150 in the gas supply means 140 to disperse the ceramic material (C), the dispersed ceramic material (C) is the only outlet It is guided to the nozzle 170 through the phosphorus delivery pipe 160.

The carrier gas is supplied and stored inside the gas supply means 140. The carrier gas may be air, oxygen (O ₂ ), nitrogen (N ₂ ), helium (He), argon (Ar), or the like, and forms a self-electrically bonded nanocomposite thick film 220 on the substrate 240. Since the influence of the type of carrier gas is not large, it is preferable to use a low-cost gas in consideration of the manufacturing cost.

And, in the embodiment of the present invention, the inflow flow rate of the carrier gas that can be introduced into the mixing vessel 130 from the gas supply means 140 is adjustable within the range of 1 L / min or more, the inflow flow rate is the nozzle 170 It can be changed according to the size.

Hereinafter, a method of manufacturing the self-electrobonding nanocomposite thick film 220 using the self-electrobonding nanocomposite thick film forming apparatus 100 configured as described above will be described with reference to FIG. 3 .

3 is a flow chart showing a method for producing a self-electrically bonded nanocomposite thick film according to the present invention.

As shown in the figure, the self-electrobonding nanocomposite thick film 220 according to the present invention, a material preparation step of charging the ceramic material (C) to the mixing vessel 130, and fixing the substrate 240 to the stage 112 (S100), the gas supply step of supplying a carrier gas into the mixing vessel 130, the ceramic material (C) and the carrier gas (S200), the carrier gas mixed in the mixing vessel 130 and Particle spraying step (S300) for transporting the ceramic material (C) to spray on the substrate 240, and to transfer the stage 112 to form a self-electrically bonded nanocomposite thick film 220 on the substrate 240 It is prepared by the self-electrobonding nanocomposite thick film forming step (S400) and the heat treatment step (S500) of growing the particle size by heat-treating the formed self-electrobonding nanocomposite thick film.

In the material preparation step (S100) of the present invention, the ceramic material (C) is applied with a mixed powder of piezoelectric ceramics and magnetostrictive ceramics. In this case, the piezoelectric ceramics and magnetostrictive ceramics may use ceramics commonly used in the art. The piezoelectric ceramics and magnetostrictive ceramics can be produced by using commercially available or by synthesizing by a conventional synthesis-oxidation method. In addition, the ceramic material (C) may be finely adjusted by varying the composition.

When the material preparation step S100 is completed, the ceramic material C is filled in the mixing vessel 130, and the substrate 240 is fixed to the bottom surface of the stage 112. After the gas supply step (S200) is carried out.

The gas supply step (S200) is a process of mixing the ceramic material (C) and the transfer gas by supplying the carrier gas stored in the gas supply means 140 into the mixing vessel 130 through the gas supply pipe 150 to be.

That is, since the flow rate of the carrier gas flowing into the mixing vessel 130 from the gas supply means 140 is carried out by adjusting within a range of 1 L / min or more, the ceramic material (C) in the mixing vessel 130 Is scattered by the inflow of carrier gas.

Meanwhile, a vacuum forming step S150 is performed between the material preparation step S100 and the gas supply step S200. The vacuum forming step (S150) is a process of operating the vacuum pump 120 to set the inside of the vacuum chamber 110 to a vacuum degree of less than 1 torr. Therefore, the carrier gas introduced into the vacuum chamber 110 by being mixed with the ceramic material C while passing through the mixing container 130 can be sucked into the vacuum pump 120.

After the gas supply step (S200), the particle injection step (S300) is carried out. The particle spraying step (S300) is a process of spraying the ceramic material (C) on the lower surface of the substrate 240 through the nozzle 170. The carrier gas and the ceramic material (C) mixed inside the mixing container 130 are provided. The ceramic material (C) is anchored and vacuum deposited on the lower surface of the substrate 240 by being sprayed upward through the nozzle 170 while sequentially passing through the transfer pipe 160 and the nozzle 170. In the particle spraying step (S300), the vacuum degree inside the mixing container 130, the transfer pipe 160 and the vacuum chamber 110 was maintained at 1-10 Torr, and the vacuum degree was differently applied depending on the flow rate of the carrier gas. Can be.

After the particle spraying step (S300), a particle recovery step (S350) for recovering the ceramic material C scattered into the vacuum chamber 110 without being deposited on the substrate 240 is performed. The ceramic material (C) recovered in the particle recovery step (S350) is collected and can be recycled again, although not shown in Figure 2 provided with a separate filtering means between the vacuum pump 120 and the vacuum chamber 110 Alternatively, the ceramic material C may be selectively filtered.

As the thickness of the deposited ceramic material C increases on the outer surface of the substrate 240, a self-electrobonding nanocomposite thick film forming step (S400) of forming a self-electrobonding nanocomposite thick film 220 is performed. The self-electrobonding nanocomposite thick film forming step (S400) forms a self-electrobonding nanocomposite thick film 220 having a thickness of 5 μm or more on the outer surface of the substrate 240, and the self-electrobonding nanocomposite thick film The thickness of 220 can be adjusted according to the implementation time of the particle injection step (S300).

The particle recovery step (S350) is preferably carried out continuously while the ceramic material (C) is injected.

After forming the self-electrically bonded nanocomposite thick film (S400), a heat treatment step (S500) is performed to heat-grow the formed self-electrically bonded nanocomposite thick film to grow a particle size. For example, by performing post-heat treatment in air at 700 ° C. for about 1 hour, crystal grains can be grown to improve self-electric coupling characteristics.

Furthermore, the present invention provides a sensor using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

In addition, the present invention provides a transducer using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

Furthermore, the present invention provides an energy harvesting apparatus using the self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

In addition, the present invention provides an electromagnetic wave shielding coating using a self-electrically bonded nanocomposite thick film composed of the piezoelectric ceramics and magnetostrictive ceramics.

The prepared self-electrobonding nanocomposite thick film is densely deposited at high density, shows no cracks or pore formation, and adheres to the substrate soundly without peeling from the substrate (see FIG. 6 ). In addition, the self-electrobonding nanocomposite thick film is a conventional thin film manufacturing process such as a high-quality dielectric constant of 200 ~ 250 (see Fig. 10 ) and a self-electric coupling output voltage coefficient of 100 mV / cm.Oe or more (see Fig. 13 ) It exhibits excellent magnetic-electric coupling properties compared to the magnetic-electric coupling composite thin film made of the present invention, and can be usefully used for sensors, transducers, energy harvester devices, and electromagnetic shielding coatings.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. The following examples are only presented to aid the understanding of the present invention, and the present invention is not limited to the following examples.

< Example > Preparation of PZNT-NCZF Self-electrobonding Nanocomposite Thick Films

0.8Pb as the ceramic material _{(C) (Zr 0 .52 Ti} 0 .48) O 3 -0.2Pb (Zn 1/3 Nb 2/3) O 3 [PZNT] powder and a (Ni _{0 .6} Cu _{0 .2 Zn 0 .2) Fe 2 O 4} [NCZF] in order to produce a powder of reagent-grade _{PbO, ZrO 2, TiO 2,} ZnO, Nb 2 O 5 And MnCO ₃ (99.9%, Sigma Aldrich Co.) and NiO, CuO, ZnO, and Fe ₂ O ₃ (99.9%, Alfa Aesar) were used. The PZNT powder and NCZF powder were prepared by synthesis by conventional synthetic-oxidation methods.

Specifically, the PZNT powder and the NCZF powder are mixed at a weight ratio of 4: 1, and then the mixed powder is charged into a mixing vessel in a thick film forming apparatus, and a rectangular nozzle having a hole of 5 × 0.04 mm ² together with a carrier gas. Spray coating at room temperature. A silicon substrate coated with a platinum electrode was fixed to a stage 5 mm away from the nozzle, and then the mixed powder was vacuum sprayed onto a platinum plated silicon substrate at room temperature to form a dense film. This process was repeated to prepare a thick film having a thickness of 10 ㎛ or more, the deposited thick film was heat-treated for 1 hour at 700 ℃ in air.

The structure of the PZNT-NCZF self-electrobonding nanocomposite thick film prepared by the above method is schematically shown in FIG. 4 .

As shown in FIG . 4 , the PZNT-NCZF self-electrobonding nanocomposite thick film has a form in which NCZF phases are dispersed in 2D connectivity in a PZNT matrix, which is difficult to achieve by other processes. It shows the compounding of connectivity.

<Characteristic Analysis>

(1) X-ray Diffraction analysis

In order to analyze the crystal phase of the PZNT-NCZF self-electrobonding nanocomposite thick film prepared by the above method was measured using an X-ray diffractometer (XRD) (D-MAX 2200, Rigaku Co., Tokyo, Japan) the results are shown in Fig.

As shown in FIG . 5 , the XRD patterns of the first starting powders were sharply present in the perovskite (PZNT) and spinel (NCZF) phases, but in the case of deposited thick films, they were broad ( broad) peak. In addition, when the thick film is heat-treated at 700 ° C, a polycrystalline composite in which a perovskite phase and a spinel phase are mixed is produced, and it can be confirmed that grain growth is achieved by heat treatment.

(2) Scanning electron microscope analysis

A PZNT-NCZF magnetic prepared by the above method - determine the cross-section of the electrical coupling nanocomposite thick film by a scanning electron microscope (SEM) (. JSM-5800 , JEOL CO, Tokyo, Japan) and the results are shown in Figure 6 .

As shown in FIG . 6 , it can be seen that the prepared PZNT-NCZF thick film was densely formed at high density, showed no cracking or pore formation, and was firmly attached to the substrate with a thickness of 10 μm or more without peeling from the substrate. have.

(3) transmission electron microscope and Electron diffraction  analysis

The cross section of the PZNT-NCZF self-electrobonding nanocomposite thick film prepared by the above method was confirmed by transmission electron microscope (TEM) and electron diffraction (SAED), and the results are shown in FIG. 7 .

As shown in FIG . 7 , it can be seen that PZNT fine particles and NCZF fine particles are well crystallized in the prepared PZNT-NCZF thick film without traces of the amorphous phase. In addition, the size of the NCZF crystal in Figure 7 was found to be in the range of 100 nm.

(4) Scanning electron microscope analysis

The cross section of the PZNT-NCZF self-electrobonding nanocomposite thick film prepared by the above method was confirmed by scanning electron microscope (STEM), and the results are shown in FIG. 8 .

The connectivity of the prepared PZNT-NCZF complex can be confirmed through FIG. 8 .

(5) EDX Mapping  analysis

EDX mapping analysis of the PZNT-NCZF self-electrobonding nanocomposite thick film prepared by the above method is shown in FIG. 9 .

In FIG. 9 , elements Pb (a) and Fe (b) represent PZNT and NCZF phases, respectively. Here, the bright region of FIG. 9 is PZNT and the dark portion represents NCZF. These results indicate that NCZF laminates are dispersed nanoscale with 2D connectivity in the PZNT matrix. The connectivity on the ferrite is not constant throughout the matrix. In addition, it can be seen that the NCZF ferrite phase and the PZNT perovskite phase do not react with each other to form a new phase.

(6) PZNT - NCZF  Self-electrobonding Nanocomposites Thick  Characterization

1) dielectric constant measurement

The dielectric constant ε _r is calculated by Equation 1 below.

(Equation 1, C is the capacitance at 1 kHz, A is the area of the electrode surface, t is the distance between the electrodes, ε _r is the dielectric constant of the material, ε _o is the dielectric constant of the vacuum.)

Dielectric constant and dielectric loss index of the PZNT-NCZF self-electrobonding nanocomposite thick film prepared by the above method were measured, and the results are shown in FIG. 10 .

As shown in FIG . 10 , the dielectric constant and dielectric loss index at 1 kHz were 237 and 0.053, respectively. This indicates that the film is of high quality. In addition, as the frequency was increased, the dielectric constant and dielectric loss index decreased, and the dielectric constant and dielectric loss index were lowered to 200 and 0.05, respectively, in the high frequency region. The dielectric properties have been shown to be very stable without any defects, which can be suitably used for sensors.

2) Ferroelectric Hysteresis curve  Measure

11 shows the electro-polarization (ferroelectric) hysteresis curve of the thick film of the PZNT-NCZF self-electrobonding nanocomposite. As shown in FIG . 11 , the prepared nanocomposite thick film increases the residual polarization value (Pr) according to the change in the size of the electric field and shows a typical ferroelectric hysteresis curve having a symmetrical shape. In addition, even if the applied electric field was 400 kV / cm, dielectric breakdown and leakage current did not occur, and the ferroelectric hysteresis characteristics were shown. The measured residual polarization value was 9 μC / cm ² and the electric field Ec was measured to have 100 kV / cm. This indirectly confirms that the prepared nanocomposite thick films have independent phases without mutual reactions and have ferroelectric properties by having high electrical resistance.

3) magnetization strength ( magentization ) And self-electric coupling voltage coefficient ( ME voltage  coefficient measurement

The NCZF with ferrimagnetic characteristics should show the magnetization-strength hysteresis behavior of the self-electrically bonded nanocomposite thick film. The PZNT-NCZF self-shown in Fig. 12, the magnetization intensity of the electric coupling nanocomposite thick film measured using a vibrating sample type magnetometer (VSM). In addition, the magnetic-electric coupling voltage coefficient was measured using an electromagnet. Specifically, the 3-2 PZNT-NCZF self-electrophoretic nanocomposite thick film was placed in the center of the Helmholtz coil and DC bias was applied, and the AC magnetic field was measured using Hac = 1.0 Oe. The self-electric coupling voltage induced in the 3-2 nanocomposite thick film was displayed on a monitor using a lock-in amplifier, and the result is shown in FIG. 13 .

As shown in Figures 12 and 13 , the maximum self-electric coupling output voltage coefficient was found to be 150 mV / cm.Oe. This size is described in JG Wan, et al: Appl. Phys. Lett. 2006, 89, 122914; H. Ryu, et al: Appl. Phys. Lett. 2006, 89, 102907; J.-P. Zhou, et al: Appl. Phys. Lett. 2006, 88, 013111; YG Ma, et al: Appl. Phys. Lett. 2007, 90, 152911, reported the maximum voltage magnitude (-40 mV / cm. About 3 times or more of Oe).

Accordingly, the 3-2 self-electrobonding nanocomposite thick film prepared according to the present invention exhibits excellent self-electric coupling properties compared to the self-electrobonding composite thin film produced by a conventional thin film manufacturing process, thereby providing a sensor, a transducer, an energy harvester device, It can be usefully used for electromagnetic shielding coating and the like.

The scope of the present invention is not limited to the above-described embodiments, and many other modifications based on the present invention will be possible to those skilled in the art within the scope of the present invention.

1 is a conceptual diagram showing the deposition principle of the self-electrobonding nanocomposite thick film according to the present invention.

Figure 2 is a schematic diagram showing the configuration of a self-electrobonding nanocomposite thick film forming apparatus for producing a self-electrobonding nanocomposite thick film according to the present invention.

Figure 3 is a flow chart illustrating a method of manufacturing a self-electrophoretic nanocomposite thick film according to the present invention.

Figure 4 is a schematic diagram showing the structure of the self-electrobonding nanocomposite thick film of the present invention.

FIG. 5 is a graph showing an XRD pattern of a thick film of a self-electrobonding nanocomposite prepared by an embodiment of the present invention.

FIG. 6 is a scanning electron microscope (SEM) photograph of a thick film of a self-electrobonding nanocomposite prepared by an embodiment of the present invention.

FIG. 7 is a transmission electron microscope (TEM) and electron diffraction (SAED) photograph (interpolated) of a self-electrically bonded nanocomposite thick film prepared by one embodiment of the present invention.

FIG. 8 is a scanning electron microscope (STEM) photograph of the thick film of the self-electrobonding nanocomposite prepared by an embodiment of the present invention.

9 is a photograph of EDX mapping analysis of the thick film of the self-electrobonding nanocomposite prepared by the embodiment of the present invention.

10 is a graph showing the dielectric constant and the dielectric loss index of the self-electrically bonded nanocomposite thick film prepared by one embodiment of the present invention with frequency.

FIG. 11 is a graph illustrating ferroelectric hysteresis curves of the thick film of the self-electrically bonded nanocomposite prepared by the embodiment of the present invention.

12 is a graph showing the magnetization strength of the self-electrobonding nanocomposite thick film prepared by one embodiment of the present invention.

FIG. 13 is a graph showing the self-electric coupling output voltage coefficients of the self-electrobonding nanocomposite thick film prepared by the embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: nanocomposite thick film forming apparatus 110: vacuum chamber

112: stage 120: vacuum pump

130: mixed container 140; Gas supply means

150: gas supply pipe 160: transfer pipe

220: nanocomposite thick film 240: substrate

C: Ceramic Material

S100: material preparation step S150: vacuum forming step

S200: gas supply step S300: particle injection step

S350: Particle Recovery Step

S400: nanocomposite thick film forming step

S500: heat treatment step

Claims (19)

A 3-2 piezoelectric ceramics-magnification ceramics self-electrobonding nanocomposite thick film in which a magnetostrictive ceramic phase is dispersed in 2D connectivity in a piezoelectric ceramic matrix. The self-electro-bonding nanocomposite thick film of claim 1, wherein the nanocomposite thick film contains 60 to 95 wt% of the piezoelectric ceramics and 5 to 40 wt% of the magnetostrictive ceramics. The self-electro-bonding nanocomposite thick film of claim 1, wherein the nanocomposite thick film has a thickness of 5 μm or more. The method of claim 1, wherein the piezoelectric ceramics are Pb (Zr, Ti) O ₃ , BaTiO ₃ , SrBi ₄ Ti ₄ O ₁₂ , (K _0.5 Na _0.5 ) NbO ₃ , PZT, PZT-PNN, PZN-PT, PZT- A self-electrically bonded nanocomposite thick film, which is selected from the group consisting of PZN, PZT-PMnN and PZNT. The method of claim 1, wherein the magnetostrictive ceramics are MnFe ₂ O ₄ , Fe ₃ O ₄ , CoFe ₂ O ₄ , MgFe ₂ O ₄ , Li _0.5 Fe ₂ O ₄ , NiFe ₂ O ₄ , CuFe ₂ O ₄ , YFe ₂ O ₄ , SmFe ₅ O ₁₂ , DyFe ₅ O ₁₂ , EuFe ₅ O ₁₂ And NCZF. A self-electrically bonded nanocomposite thick film characterized in that it is selected from the group consisting of. The method of claim 1, wherein the piezoelectric ceramic is _{0.8Pb (Zr 0 .52 Ti 0 .48} ) O 3 -0.2Pb (Zn 1/3 Nb 2/3) O 3 and [PZNT], the magnetostrictive ceramics (Ni electrical coupling nanocomposite thick _{- 0 .6 Cu 0 .2 Zn 0} .2) Fe 2 O 4 [NCZF] self, characterized in that. The self-electro-bonding nanocomposite thick film of claim 1, wherein the nanocomposite thick film has a dielectric constant (ε _r ) of 200 to 250. 3. The film of claim 1, wherein the nanocomposite thick film has a maximum self-electrically coupled output voltage coefficient of at least 100 mV / cm.Oe. delete A material preparation step of charging a ceramic material to a mixing container and fixing a substrate to a stage (S100); A gas supply step of supplying a carrier gas into the mixing container to mix a ceramic material and a carrier gas (S200); Particle spraying step (S300) for transporting the mixed carrier gas and the ceramic material in the mixing vessel and spraying on the substrate; Transporting the stage to form a nanocomposite thick film on a substrate (S400); And The method of manufacturing the self-electrobonding nanocomposite thick film of claim 1, wherein the nanocomposite thick film is subjected to a heat treatment step (S500) of heat-treating the formed nanocomposite thick film. The method of claim 10, wherein the ceramic material is a mixed powder of piezoelectric ceramics and magnetostrictive ceramics. The method of claim 11, wherein the piezoelectric ceramics are Pb (Zr, Ti) O ₃ , BaTiO ₃ , SrBi ₄ Ti ₄ O ₁₂ , (K _0.5 Na _0.5 ) NbO ₃ , PZT, PZT-PNN, PZN-PT, PZT- A method for producing a self-electrically bonded nanocomposite thick film, which is selected from the group consisting of PZN, PZT-PMnN and PZNT. The method of claim 11, wherein the magnetostrictive ceramics are MnFe ₂ O ₄ , Fe ₃ O ₄ , CoFe ₂ O ₄ , MgFe ₂ O ₄ , Li _0.5 Fe ₂ O ₄ , NiFe ₂ O ₄ , CuFe ₂ O ₄ , YFe ₂ O ₄ , SmFe ₅ O ₁₂ , DyFe ₅ O ₁₂ , EuFe ₅ O ₁₂ And NCZF. The method of manufacturing a self-electrobonding nanocomposite thick film characterized in that it is selected from the group consisting of. According to claim 11, wherein the piezoelectric ceramic is _{0.8Pb (Zr 0 .52 Ti 0 .48} ) O 3 -0.2Pb (Zn 1/3 Nb 2/3) O 3 [PZNT] , and wherein the magnetostrictive ceramics (Ni _{0 .6 Cu 0 .2 Zn 0 .2} ) Fe 2 O 4 [NCZF] self, characterized in that - the electrical coupling method of producing a nanocomposite thick. The method of claim 10, wherein the ceramic material comprises 60 to 95 wt% of piezoelectric ceramics and 5 to 40 wt% of magnetostrictive ceramics. Magnetic sensor using the self-electrobonding nanocomposite thick film of claim 1. Magnetic-electric converter using the self-electrobonding nanocomposite thick film of claim 1. Energy harvesting apparatus using the self-electrobonding nanocomposite thick film of claim 1. delete

Images