KR100904204B1 - Ferromagnetic Single-crystalline Metal Nanowire and the Fabrication Method Thereof - Google Patents

Abstract

The present invention provides a method for producing a ferromagnetic metal single crystal nanowire using a metal halide as a precursor and a ferromagnetic metal single crystal nanowire, and specifically, the precursor placed at the front end of the reactor and the rear end of the reactor. Provided are a manufacturing method of forming a ferromagnetic metal single crystal nanowire on the substrate by heat-treating the substrate in an atmosphere where an inert gas flows, and a ferromagnetic metal single crystal nanowire manufactured by the manufacturing method of the present invention.

In the method of the present invention, ferromagnetic metal single crystal nanowires can be prepared by using a gas phase transfer method without using a catalyst, and the process is simple and reproducible, and the prepared nanowires do not contain defects and impurities. The high purity ferromagnetic metal nanowires are in a state of high purity and have the advantage of mass production of ferromagnetic metal nanowires of uniform size that are not aggregated on a substrate. In addition, the anti-oxidation film is formed on the surface has the advantage of being a stable ferromagnetic metal nanowires to prevent the oxidation of the ferromagnetic metal.

Ferromagnetic metal, nanowire, single-crystalline, magnetic, Co, Ni, Fe

Description

Ferromagnetic Single-crystalline Metal Nanowire and the Fabrication Method Thereof}

The present invention relates to a method for producing ferromagnetic metal single crystal nanowires by vapor phase transfer method using metal halides as precursors, and to ferromagnetic metal single crystal nanowires.

1D nanostructures represented by nanowires are attracting attention as materials with various application possibilities. That is, these nanostructures are new due to their reduced size, increased aspect ratio and increased surface to volume ratio, and new morphologies. It is expected to show unique properties that are not observed in phenomena or bulk.

In particular, ferromagnetic metal nanowires represented by cobalt, nickel, iron, etc., among these one-dimensional nanostructure materials, include ultrahigh-density magnetic recording, ultrafast optical switching, and microwave devices. It is attracting much attention because of potential applications such as (microwave devices).

However, unlike other semiconductor nanowires, metal nanowires are not only difficult to synthesize, but even if they are successfully synthesized, except for a few precious metals, oxidation occurs immediately and loses the properties of the metal itself. Suffer. Much effort is underway to prevent this, and it remains a big challenge that must be resolved in the future.

The main interest in the papers reported so far focuses on the synthesis of nanoscale structures using bulk magnetic metals. For the synthesis of one-dimensional nanostructures, most groups use the easiest method, Anodic aluminum oxide template. This method is the most convenient for synthesizing one-dimensional nanostructures, and has been spotlighted in terms of diameter control of nanowires depending on the synthesis conditions, but it is difficult to synthesize single-crystalline nanowires. There are disadvantages.

The synthesis of single crystal nanowires is an important factor in terms of the electrical and magnetic properties of the material. The most important consideration in the electrical properties of nanowires is the degree of electron conductivity. In the case of single crystal nanowires, since there is no obstacle to electron conduction inside the nanowire because the nanowire itself is one large grain boundary, in the case of polycrystalline nanowires, many grains and grain boundaries exist. As the electrons are conducted along the nanowires, many boundary barriers cause scattering of electrons, thereby degrading electron conductivity. In addition, in the magnetic properties of nanowires, the arrangement of electron spin is a very important factor when an external field is applied to the nanowires. As mentioned above, in the case of a single crystal, only one crystal is used, so all the spins of electrons are arranged in a constant direction when an external magnetic field is applied. As a result, an electron spin array is formed, which eventually acts as a factor to lower magnetic properties.

In order to solve these problems, the present inventors attempted a gas phase synthesis method using a metal halide precursor, and was able to synthesize magnetic metal nanowires such as Co and Ni having a perfect structure of a single crystal, in particular, a sapphire substrate. When the silicon substrate is placed underneath, the silicon supplied from the silicon substrate forms a silica (SiO _x ) film on the surface of the metal nanowire, thereby synthesizing a new nanowire to prevent further oxidation.

An object of the present invention for solving the above problems is to provide a high-purity, high-quality ferromagnetic metal single crystal nanowires and a method of manufacturing the same by using a gas phase transfer method without using a catalyst, and furthermore, an oxidation-resistant ferromagnetic metal single crystal It is to provide a nanowire and a method of manufacturing the same. Still another object of the present invention is to provide a device with ferromagnetic metal single crystal nanowires of the present invention.

The ferromagnetic metal single crystal nanowires of the present invention are prepared using a gas phase synthesis method in a non-catalytic condition using a precursor containing a metal halide, and a passivation layer on the surface of the ferromagnetic metal single crystal nanowires. This feature is formed. The antioxidant film is preferably a silica film, the silica film has a thickness of 1 to 5 nm.

The ferromagnetic metal single crystal nanowires of the present invention are Co, Ni or Fe. The ferromagnetic metal single crystal nanowires are Co single crystal nanowires having a hexagonal close-packed (HCP) structure and have a silica film formed on the surface of the Co single crystal nanowires. The ferromagnetic metal single crystal nanowires are Ni single crystal nanowires of face centered cubic (FCC).

In the gas phase synthesis method, the precursor is maintained at 500 to 1200 ° C., the substrate on which the ferromagnetic metal single crystal nanowires are formed is maintained at 800 to 1100 ° C., and the inert gas is moved from the precursor to the substrate at a pressure of 400 to 800 torr. 20 to 150 sccm is characterized by being manufactured by flowing heat treatment.

In the method of manufacturing the ferromagnetic metal single crystal nanowires of the present invention, a precursor including metal halides positioned at the front end of the reactor and a substrate positioned at the rear end of the reactor are heat-treated in an atmosphere of inert gas flow. A ferromagnetic metal nanowire of a single crystal is formed on the surface of the substrate, wherein the substrate is a non-conductive single crystal substrate, or the substrate is composed of a non-conductive single crystal substrate and a silicon single crystal substrate to form the non-conductive single crystal on the silicon single crystal substrate. It is a board | substrate with which the board | substrate is laminated | stacked. In this case, the non-conductive single crystal substrate is preferably a sapphire single crystal substrate.

The heat treatment is the precursor is maintained at 500 to 1200 ℃ and the substrate is maintained at 800 to 1100 ℃, the heat treatment is flowing the inert gas 20 to 150 sccm from the front end of the reactor toward the rear end of the reactor The heat treatment is characterized in that it is treated at a pressure of 400 to 800 torr.

The precursor metal halide is preferably selected from metal fluoride, metal chloride, metal bromide or metal iodide, and the metal halide is halogenated. Cobalt, nickel halide or iron halide.

The precursor is cobalt halide, and the ferromagnetic metal single crystal nanowires produced are Co single crystal nanowires, wherein the precursor is preferably maintained at 500 to 800 ° C.

The precursor is nickel halide, and the ferromagnetic metal single crystal nanowire is Ni single crystal nanowire, wherein the precursor is preferably maintained at 800 to 1200 ° C.

The ferromagnetic metal single crystal nanowire of the present invention or the ferromagnetic metal single crystal nanowire manufactured by the manufacturing method of the present invention is provided in a device including a magnetic recording device, an optical device or an microwave device to provide a magnetic recording device, an optical device or an microwave device. to provide.

In the method of the present invention, ferromagnetic metal nanowires can be manufactured by using a gas phase transfer method without using a catalyst, and thus the process is simple and reproducible, and a perfect single crystal state in which the manufactured nanowires do not contain defects and impurities is produced. The high purity high quality ferromagnetic metal nanowires have the advantage of being able to mass-produce ferromagnetic metal nanowires of uniform size that are not aggregated on a single crystal substrate. In addition, the anti-oxidation film is formed on the surface has the advantage of being a stable ferromagnetic metal nanowires to prevent the oxidation of the ferromagnetic metal. In addition, by providing a ferromagnetic metal having a magnetic form in the form of single crystal nanowires, it provides a way to use high-speed, high-efficiency, low-power, miniaturized electrical devices, magnetic devices and optical devices using the same.

In the method of manufacturing a ferromagnetic metal single crystal nanowire of the present invention, a precursor material including a transition metal halide positioned at a front end of a reactor and a substrate placed at a rear end of a reactor are heat-treated in an atmosphere of flowing inert gas. As a result, a single crystal ferromagnetic metal nanowire is formed on the surface of the substrate.

The manufacturing method of the present invention is a method of forming ferromagnetic metal nanowires on a substrate by simply using a metal halide as a precursor without using a catalyst, and using ferromagnetic metal single crystal nanowires through a material movement path without using a catalyst. Since the process is simple and reproducible, there is an advantage that can produce a high-purity nanowire containing no impurities.

In addition, by controlling the temperature of the front end of the reactor and the rear end of the reactor, respectively, the degree of flow of the inert gas and the pressure in the heat treatment tube used during the heat treatment to finally control the nucleation driving force, growth driving force of the ferromagnetic metal material on the substrate As a method of controlling the rate of nucleation and growth, the size of the ferromagnetic metal single crystal nanowires and the density on the substrate can be controlled, reproducible, defect-free, and high-quality ferromagnetic metal single crystal nanowires can be produced. It becomes possible.

A metal halide may be used as a precursor for producing ferromagnetic metal nanowires, and the metal halide may use cobalt halide, nickel halide or iron halide.

The metal halide is preferably selected from metal fluoride, metal chloride, metal bromide or metal iodide, and more preferably metal chloride, metal bromide or metal iodide. Is preferably selected, most preferably metal chloride.

The cobalt halide is cobalt fluoride, cobalt chloride, cobalt bromide or cobalt iodide, and most preferably cobalt chloride is used. The nickel halide is nickel fluoride, nickel chloride, nickel bromide or nickel iodide, most preferably nickel chloride. The iron halide is iron fluoride, iron chloride, iron bromide or iron iodide, most preferably iron chloride.

As described above, the core of the present invention is to prepare ferromagnetic metal nanowires by using a metal halide as a precursor without using a catalyst and by using a vapor phase transfer method. The most important key conditions for the production are the temperature of the front end of the reactor and the rear end of the reactor, the degree of flow of the inert gas, and the pressure conditions during the heat treatment.

The heat treatment temperature conditions, carrier gas flow rate and pressure conditions during the heat treatment may be independently changed, but the three conditions must be changed depending on the conditions of the other conditions of the desired quality and shape. Ferromagnetic metal single crystal nanowires can be obtained.

Therefore, rather than the numerical limitation of the three conditions independently have a meaning, it is the method of manufacturing the most preferred ferromagnetic metal single crystal nanowires in the three conditions combined.

The temperature of each of the front end of the reactor (precursor) and the rear end of the reactor (substrate) depends on the physical properties such as melting point, vaporization point and vaporization energy of the precursor, the flow conditions of the inert gas and the pressure conditions at the time of heat treatment. Although it should be optimized, preferably the temperature of the reactor front end (precursor) is 500 to 1200 ℃, the temperature of the reactor rear end (substrate) is preferably 800 to 1100 ℃.

The inert gas is preferably flowed from 20 to 150 sccm from the front end of the reactor (precursor) toward the rear end of the reactor (substrate), more preferably from 50 to 100 sccm.

The pressure during the heat treatment is preferably a pressure range similar to the normal pressure, more preferably the pressure of the heat treatment is more preferably 400 to 800 torr, most preferably 400 to 760 torr.

The reaction temperature of the reactor, the flow conditions of the inert gas, and the pressure conditions during the heat treatment are the degree of vaporization of the precursor, the amount of vaporized precursor delivered to the substrate per hour, nucleation and growth rate of the ferromagnetic metal material on the substrate, on the substrate It affects the surface energy of the produced ferromagnetic metal material (nanowire), the degree of aggregation of the ferromagnetic metal material (nanowire) produced on the substrate, and the morphology of the ferromagnetic metal material formed on the substrate.

Therefore, the ferromagnetic metal nanowires can be manufactured in the most desirable quality and shape by the vapor phase transfer method using the precursor of the present invention under the above temperature, flow of inert gas and pressure under heat treatment. When the condition is out of the above range, quality problems such as agglomeration, shape change, and defects of the manufactured nanowires may occur, and there is a problem of obtaining metal bodies such as particles and rods, which are not in the form of nanowires. have.

The heat treatment time should also be optimized according to the temperature, the flow of inert gas, and the pressure conditions during the heat treatment, and preferably heat treatment for 5 minutes to 1 hour. During the heat treatment time, the precursor vaporized by the inert gas moves to the substrate to participate in nucleation and growth, but at the same time, the material transfer (atomic or Mass transfer in clusters) and Ostwald ripening.

Therefore, after the heat treatment, the substrate on which the ferromagnetic metal nanowires are formed may be heat-treated again to remove the precursors, thereby controlling the density and size of the ferromagnetic metal nanowires.

As described above, the manufacturing method of the present invention is to use a metal halide as a precursor, and to propose a vapor phase transfer method for producing ferromagnetic metal nanowires using the precursor, which can be used in the manufacturing method. The precursor material can be any halogenated transition metal, and all ferromagnetic metal single crystal nanowires can be manufactured using the precursor. In addition, in the halogenated transition metal, which is a precursor, the metal is Sc, Ti, using a halogenated transition metal selected from Sc, Ti, V, Cr, Mn, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh or Cd. Paramagnetic or ferromagnetic single crystal metal nanowires of V, Cr, Mn, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh or Cd may be prepared.

The substrate may be used as long as it is a chemically / thermally stable single crystal insulator under the above heat treatment conditions, but preferably, a single crystal substrate selected from sapphire (Al ₂ O ₃ ) single crystal or silicon dioxide (SiO ₂ ) single crystal is used. . In the case of using a single crystal substrate, the surface of the substrate may be used in any crystallographic manner, and a polycrystal of sapphire or silicon dioxide may be used as the substrate.

Another feature of the method of manufacturing the ferromagnetic metal single crystal nanowires of the present invention is to form an passivation layer on the surface of the ferromagnetic metal single crystal nanowires.

Such an anti-oxidation film prevents oxidation of the ferromagnetic metal single crystal nanowires, thereby allowing the electrical / magnetic properties and physical properties to be maintained at unique values of the ferromagnetic metal. The antioxidant film is preferably a silicon oxide film (SiO _x , where x is 1 ≦ x ≦ 2).

The method of manufacturing the ferromagnetic metal single crystal nanowires having the antioxidant film formed thereon is the same as the method of manufacturing the ferromagnetic metal single crystal nanowires except for the substrate used.

The substrate used to form the anti-oxidation film is composed of a non-conductive single crystal substrate and a silicon single crystal substrate, and the non-conductive single crystal substrate is stacked on the silicon single crystal substrate. The non-conductive substrate stacked on the silicon single crystal substrate is preferably a sapphire single crystal substrate or a silicon dioxide single crystal substrate. 1 shows a method of manufacturing a ferromagnetic metal single crystal nanowire having an antioxidant film formed thereon. As shown in FIG. 1, the precursor including the metal halide is maintained at 500 to 1200 ° C., and the laminated substrate on which the ferromagnetic metal single crystal nanowires are formed is maintained at 800 to 1100 ° C., and has a pressure of 400 to 800 torr. In the precursor material is prepared by a heat treatment flowing 20 to 150 sccm inert gas toward the substrate, the laminated substrate is a non-conductive single crystal substrate is stacked on top of the silicon single crystal substrate, the silicon of the silicon single crystal substrate material transfer to ferromagnetic The silicon oxide film is formed on the surface of the metal single crystal nanowire.

In order to experimentally prove the superiority of the production method of the present invention, Co single crystal nanowires (Example 1) and Co single crystal nanowires (Example 1) in which an antioxidant film was formed using cobalt chloride as a precursor according to the production method of the present invention (Example 2) ) And Ni single crystal nanowires (Example 3) were prepared using nickel chloride as a precursor.

At this time, as described above, the temperature of each of the front end of the reactor and the rear end of the reactor should be optimized according to physical properties such as melting point, vaporization point, and vaporization energy of the precursor and ferromagnetic metal, so that cobalt chloride is used as the precursor. In the case of preparing Co single crystal nanowires, the temperature of the front end of the reactor (precursor) is maintained at 500 to 800 ° C., and the temperature of the rear end of the reactor (substrate) is preferably maintained at 800 to 1100 ° C. . When preparing Ni single crystal nanowires using nickel chloride as a precursor, the temperature of the front end of the reactor (precursor) is maintained at 800 to 1200 ° C., and the temperature of the rear end of the reactor (substrate) is 800 to 1100. It is preferably kept at 占 폚.

In Examples 1, 2, and 3 below, CoCl ₂ (Examples 1 and 2) and NiCl ₂ (Example 3) were used as precursors, respectively.

(Example 1)

Co single crystal nanowires with an anti-oxidation film were synthesized by using a gas phase transfer method in a reactor.

The reactor is divided into a front end and a rear end, and is independently provided with a heating element and a temperature control device. The tube in the reactor was made of quartz (Quzrtz) material with a diameter of 1 inch and a length of 60 cm.

A boat vessel made of high purity alumina containing 0.05 g of precursor CoCl ₂ (Sigma-Aldrich, 409332) was placed in the center of the front end of the reactor, and a stacked substrate was placed in the center of the rear end of the reactor. The stacked substrate is composed of a silicon substrate (1.5 cm x 4 cm) and a sapphire substrate (0.5 cm x 0.5 cm), the sapphire substrate is stacked on top of the silicon substrate.

Argon gas is introduced into the front end of the reactor and exhausted to the rear end of the reactor, and a vacuum pump is provided at the rear end of the reactor. The vacuum pump was used to maintain a pressure in the quartz tube at 500 torr, and 100 sccm of Ar was flowed using a Mass Flow Controller (MFC).

The temperature of the front end of the reactor (the alumina boat containing the precursor) was maintained at 650 ° C, and the temperature of the rear end of the reactor (substrate) was maintained at 950 ° C for 20 minutes, followed by heat treatment for 20 minutes. Wire was prepared.

(Example 2)

Co single crystal nanowires were prepared using the same conditions and apparatus as in Example 1, except that the degree of argon gas flow, pressure, substrate, and heat treatment time were used.

Argon gas was allowed to flow from the front end to the rear end of the reactor at 50 sccm, the pressure inside the heat treatment tube was maintained at 760 torr at atmospheric pressure, and a sapphire single crystal substrate was used instead of the substrate stacked on the substrate. Nanowires were prepared.

(Example 3)

Ni single crystal nanowires were manufactured using the same conditions and apparatus as in Example 1, except for the precursors, the pressure, the substrate, the annealing temperature, and the annealing time.

0.05 g of NiCl ₂ (Sigma-Aldrich, 451193) was used as the precursor, and the pressure in the heat treatment tube was maintained at 760 torr at normal pressure, and a sapphire single crystal substrate was used instead of the substrate stacked on the substrate. Material) was maintained at 1100 ℃, the temperature of the rear end (substrate) of the reactor was maintained at 1000 ℃ heat treatment for 30 minutes to prepare Ni single crystal nanowires.

The ferromagnetic metal single crystal nanowires prepared in Examples 1 to 3 were analyzed to analyze the quality, shape, and purity of the ferromagnetic metal single crystal nanowires manufactured by the manufacturing method of the present invention.

2 to 6 are measurement results using Co nanowires formed with a silicon oxide film prepared in Example 1. FIG.

FIG. 2 is a SEM (Scanning Electron Microscope) photograph of a Co nanowire having a silicon oxide film formed on a sapphire single crystal substrate, and as shown in FIG. It can be seen that it is manufactured separately, Co nanowires having a shape extending straight in the direction of the long axis of the nanowires and the silicon oxide film is formed separately separated without agglomeration of the nanowires is produced.

FIG. 3A is a TEM (Transmission Electron Microscope) photograph of a Co nanowire having a silicon oxide film formed thereon, and FIG. 3B is a High Resolution TEM (HRTEM) photograph of a Co nanowire having a silicon oxide film formed thereon, illustrated in FIG. 3B. 3A illustrates a selected area electron diffraction pattern (SAED) of a Co nanowire on which a silicon oxide film of FIG. 3A is formed. As can be seen in Figure 3a it can be seen that the nanowires produced have a smooth surface and grow straight on the major axis and have a uniform thickness. It can be seen that the nanowires manufactured through SAED of FIG. 3B are single crystal nanowires composed of single crystals, and have a hexagonal close-packed (HCP) structure and a growth direction of <001>. In addition, it can be seen from the HRTEM photograph of FIG. 3B that the high-quality single crystal nanowires are free of defects or defects.

FIG. 4 is a TEM photograph showing that a silicon oxide film is formed on a surface of a nanowire, and FIG. 5 is a result of component analysis of the silicon oxide part using EDS (Energy Dispersive Spectroscopy) attached to a TEM device. As can be seen from the results of FIG. 5, except that the material, which is incidentally measured due to the characteristics of the measuring equipment, such as a grid, a silicon oxide film made of pure silicon and oxygen has a uniform thickness formed on the surface of Co nanowires. Can be. As can be seen in the photo of FIG. 4, a silicon oxide film having a thickness of about 3 nm is formed, the silicon oxide film formed on the surface of the ferromagnetic metal nanowire has a thickness of 1 to 5 nm and surrounds the ferromagnetic metal nanowire with a predetermined thickness.

FIG. 6 is an EDS result of Co nanowires on which silicon oxide films are formed. As shown in FIG. 6, nanowires are pure Co except for a material measured by a secondary material due to characteristics of measurement equipment such as a grid and a silicon oxide film. It can be seen that consists of.

The ferromagnetic metal nanowires having the anti-oxidation film formed through the results of FIGS. 2 to 6 are high-quality single crystals, and have high purity and solidity. The anti-oxidation film, in particular, the silicon oxide film is formed to have a uniform thickness on the ferromagnetic metal nanowire surface. And has a thickness of 3 to 10 nm.

Figure 7 is a SEM photograph of the Co nanowires prepared in Example 2. As can be seen from Figure 7 it can be seen that a large amount of Co nanowires are manufactured by separating the sapphire single crystal substrate in a uniform size, and has a shape extending straight in the long axis direction of the nanowires and can be separated separately without aggregation of nanowires. It can be seen that the nanowires were produced. In addition, it can be seen that Co nanowires having an orientation in which the long axis of the nanowires are perpendicular to the surface of the substrate are manufactured.

8 to 11 show measurement results using Ni nanowires prepared in Example 3. FIG.

FIG. 8 is an SEM photograph of Ni nanowires prepared on a sapphire single crystal substrate. As can be seen from FIG. 8, it can be seen that a large amount of Ni nanowires are separated from a sapphire single crystal substrate in a uniform size, and the long axis direction of the nanowires. It can be seen that Ni nanowires having a straight shape and having separate nanowires are formed separately without aggregation of nanowires, and Ni nanowires having an orientation in which the long axis of the nanowires are perpendicular to the surface of the substrate are manufactured.

9 shows X-Ray Diffraction (XRD) results of Ni nanowires. In the diffraction result of FIG. 9, the peak having the largest diffraction intensity is due to the sapphire substrate, and the Ni nanowires have a face centered cubic structure (FCC) through the diffraction pick except the pick by the sapphire substrate. It can be seen that.

FIG. 10 is a TEM image of Ni nanowires, and a figure inserted in the upper right of FIG. 10 is a limited field electron diffraction pattern (SAED) of the Ni nanowires of FIG. 10. As can be seen in FIG. 10, the prepared nanowires have a smooth surface, grow straight with a long axis, and have a uniform thickness. Unlike FIG. 4, it can be seen that an oxide layer is not formed on the surface. In addition, it can be seen from the SAED of FIG. 10 that the Ni nanowires are single crystal nanowires composed of single crystals, face centered cubic (FCC), and a growth direction (long axis) is <001>.

FIG. 11 shows EDS results of Ni nanowires. As can be seen from FIG. 11, it can be seen that nanowires are made of pure Ni except for a material that is additionally measured due to characteristics of a measuring device such as a grid.

7 to 11 show that the ferromagnetic metal nanowires of the present invention are high quality single crystals having a bulky crystal structure, have high purity and solid shape, and have long axes of the nanowires perpendicular to the surface of the substrate. It can be seen that ferromagnetic metal nanowires having an orientation close to and having an anti-oxidation film formed on the surface thereof, which can maintain the physical, electrical, and magnetic properties of the ferromagnetic metal depending on the substrate material.

The ferromagnetic metal nanowires production method of the present invention and the ferromagnetic metal nanowires produced by the production method of the present invention is controlled, reproducible and by providing a large amount of high purity, high quality and solid single crystal nanowires through a simple manufacturing process The ferromagnetic metal nanowires are provided with a scaffold capable of studying physical, optical and electromagnetic properties thereof, and the ferromagnetic metal nanowires of the present invention having magnetic properties and ferromagnetic metal nanowires prepared by the method of the present invention are provided. The characteristics and the efficiency of the element including the magnetic recording element, the optical element or the microwave element can be improved and the size thereof can be reduced.

1 is a schematic diagram showing a manufacturing method of the present invention,

2 is a SEM (Scanning Electron Microscope) photograph of the Co nanowires formed with a silicon oxide film prepared according to Example 1 of the present invention,

3 is a transmission electron microscope (TEM) picture of a Co nanowire having a silicon oxide film formed through Example 1 of the present invention, 3a is a bright field image of a Co nanowire having a silicon oxide film formed thereon, and FIG. 3b is FIG. 3a. HRTEM (High Resolution TEM) photo of the nanowire of Figure 3b is a picture inserted in the upper right of Figure 3a is a limited field electron diffraction pattern (SAED) of the Co nanowires formed silicon oxide film of Figure 3a,

4 is a TEM photograph showing that a silicon oxide film of Co nanowires formed with a silicon oxide film prepared according to Example 1 of the present invention is formed,

5 is a component analysis result of the silicon oxide film portion using EDS (Energy Dispersive Spectroscopy) attached to the TEM device of the Co nanowires formed silicon oxide film prepared in Example 1 of the present invention,

6 is an EDS result of Co nanowires formed with a silicon oxide film prepared according to Example 1 of the present invention.

7 is a SEM photograph of a Co nanowire manufactured through Example 2 of the present invention.

FIG. 8 is an SEM photograph of Ni nanowires prepared through Example 3 of the present invention.

9 is an XRD (X-Ray Diffraction) result of Ni nanowires prepared through Example 3 of the present invention.

FIG. 10 is a TEM photograph of the Ni nanowires prepared through Example 3 of the present invention, and the figure inserted in the upper right of FIG. 10 is a limited field electron diffraction pattern (SAED) of the Ni nanowires of FIG. 10.

11 is an EDS result of Ni nanowires prepared through Example 3 of the present invention.

Claims (24)

It is a monocrystalline ferromagnetic metal single crystal nanowire manufactured by vapor phase synthesis in a non-catalytic condition using a precursor containing a metal halide, and an antioxidant layer is formed on the surface of the ferromagnetic metal single crystal nanowire. Ferromagnetic metal single crystal nanowires, which are formed. delete The method of claim 1, The anti-oxidation film is a ferromagnetic metal single crystal nanowires, characterized in that the silica film. The method of claim 3, wherein The silica film has a thickness of 1 to 5 nm ferromagnetic metal single crystal nanowires. The method of claim 1, The ferromagnetic metal single crystal nanowires are Co, Ni or Fe ferromagnetic metal single crystal nanowires. The method of claim 1, The ferromagnetic metal single crystal nanowire is a ferromagnetic metal single crystal nanowire, characterized in that the Co single crystal nanowires of Hexagonal Close-Packed (HCP). The method of claim 6, Ferromagnetic metal single crystal nanowires, characterized in that a silica film is formed on the surface of the Co single crystal nanowires. The method of claim 1, The ferromagnetic metal single crystal nanowire is a ferromagnetic metal single crystal nanowire, characterized in that the Ni single crystal nanowires of the Face Centered Cubic (FCC). The method of claim 1, In the gas phase synthesis method, the precursor is maintained at 500 to 1200 ° C., the substrate on which the ferromagnetic metal single crystal nanowires are formed is maintained at 800 to 1100 ° C., and the inert gas is moved from the precursor to the substrate at a pressure of 400 to 800 torr. The ferromagnetic metal single crystal nanowires, which are prepared by heat treatment flowing 20 to 150 sccm. A single crystal ferromagnetic metal nanowire is formed on the surface of the substrate by heat-treating a precursor including metal halide positioned at the front end of the reactor and a substrate positioned at the rear end of the reactor under an inert gas flow. Method for producing a ferromagnetic metal single crystal nanowires, characterized in that is formed. The method of claim 10, The substrate is a method of manufacturing a ferromagnetic metal single crystal nanowires, characterized in that the non-conductive single crystal substrate. The method of claim 10, The substrate comprises a non-conductive single crystal substrate and a silicon single crystal substrate, wherein the non-conductive single crystal substrate is laminated on the silicon single crystal substrate. The method of claim 10, The heat treatment is a method of manufacturing a ferromagnetic metal single crystal nanowires, the precursor is maintained at 500 to 1200 ℃ and the substrate is maintained at 800 to 1100 ℃. The method of claim 13, The heat treatment is a method for producing a ferromagnetic metal single crystal nanowires, characterized in that for flowing the inert gas 20 to 150 sccm from the front end of the reactor toward the rear end of the reactor. The method of claim 14, The heat treatment is a method of producing a ferromagnetic metal single crystal nanowires, characterized in that the treatment at a pressure of 400 to 800 torr. The method of claim 10, The metal halide is a method of manufacturing a ferromagnetic metal single crystal nanowire, characterized in that selected from metal fluoride, metal chloride, metal bromide, or metal iodide. The method of claim 16, The metal halide is a method for producing a ferromagnetic metal single crystal nanowire, characterized in that cobalt halide, nickel halide or iron halide. The method of claim 10, The precursor is cobalt halide, and the ferromagnetic metal single crystal nanowire is a Co single crystal nanowire manufacturing method of the ferromagnetic metal single crystal nanowire. The method of claim 18, The precursor material is a method of producing a ferromagnetic metal single crystal nanowires, characterized in that maintained at 500 to 800 ℃. The method of claim 10, The precursor is nickel halide, and the ferromagnetic metal single crystal nanowires are Ni single crystal nanowires. The method of claim 20, The precursor material is a method of producing a ferromagnetic metal single crystal nanowires, characterized in that maintained at 800 to 1200 ℃. The method of claim 11 or 12, The non-conducting single crystal substrate is a sapphire single crystal substrate, characterized in that the ferromagnetic metal single crystal nanowire manufacturing method. delete delete

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