KR102032918B1 - Novel magnetocaloric materials and preparation method thereof - Google Patents

Abstract

The present invention relates to a novel magnetocaloric material and a method of manufacturing the same, and more particularly, to a novel magnetocaloric material represented by Formula 1 below:
[Formula 1]
(Gd _{1 - x} A _x ) ₃ SnC
(Wherein A is La or Ce, x is a minor number and 0 < x < 1), and a method for producing the novel magnetocaloric material using the Arc melting method.
The magnetothermal material according to the present invention shows an increased magnetothermal effect and at the same time has a significantly higher efficiency than the metal Gd ₃ SnC of the same volume of raw material, thereby implementing a low-cost, high-efficiency self-cooling device and extending the application temperature range of the magnetothermal effect. It can be useful for control.

Description

Novel magnetocaloric materials and preparation method

The present invention relates to a novel magnetic heat material, and more particularly, to a novel material having a magnetocaloric effect that absorbs heat when the magnetic field is applied and, on the contrary, absorbs heat when the magnetic field is removed, thereby cooling the surroundings. It relates to a manufacturing method.

Currently, the commonly used cooling technology is to repeat the process of compressing, condensing, expanding, and evaporating a refrigerant to take the temperature out of the system. CFCs, HCFCs, ammonia, etc. are widely used as a refrigerant gas, but a lot of energy is consumed in the process of compressing gas, low efficiency, can cause environmental problems such as air pollution by the greenhouse effect.

The magnetocaloric cooling method is a cooling method using a solid state material, which is environmentally friendly and has a high cooling efficiency since it does not use a gaseous refrigerant.

In the magnetothermal cooling method, when a magnetic field is applied to a magnetic heat material from the outside, the magnetic moments in the material are aligned, and the effect thereof can be evaluated based on the change of entropy in the process. Although a Gd element is used as a representative magnetocaloric material, Gd is expensive, and thus, it is difficult to commercialize a magnetocaloric cooling method.

Electronide is a new concept of material in which electrons exist as interstitial electrons in an empty space inside a crystal, not around an atomic nucleus, and directly determine the functionality of a material regardless of constituent elements and structural factors.

E-cargo can be used as an electron-emitting material with low work function, and can be used as a magnetic material (light magnetic material, magnetic heat material, etc.) due to high magnetic entropy change, and widely used as catalyst material due to high electron transfer efficiency It can be a substance.

The electronics are divided into organic and inorganic electronics. The developed organic electronics are unstable at room temperature and thus cannot be used as electronic materials. The inorganic electronics stable at room temperature are C ₁₂ A ₇ or 12CaO _l2 developed in 2003. O ₃ is a representative example, and a Japanese patent company has recently developed a patent application for nitride electronics (AE ₃ N) (JP2014-024712, JP2012-166325). In Korea, a patent application for C ₁₂ A ₇ has been filed by Korea Ceramic Technology Institute (KR2013-0040232, etc.), but no inorganic electronic cargo containing other components has been reported.

In addition, it is difficult to design and synthesize a composition that can be embodied as a material having electrons in a specific space inside a crystal, which is completely different from the conventional stoichiometric material concept, and the physical properties are dependent on the constituent elements and structural characteristics. There are also technical limitations in predicting its functional characteristics due to its sensitivity to change, so the case of research until now is very rare.

US Patent No. 6589366 Korean Patent Publication No. 2015-0042029

The present invention provides a Gd-based composite material capable of securing a high price competitiveness compared to the metal Gd ₃ SnC of the same volume by controlling the high-performance magnetothermal effect and the magnetic moment per unit element and the application temperature range of the magnetothermal effect For expansion and control purposes.

It is also an object of the present invention to provide a method for producing the Gd-based composite material.

In order to achieve the above object, the present inventors have developed an electronide (Gd _1-x A _x ) ₃ SnC (where A is La or Ce, x is prime and 0 <x <1). The present invention was completed by confirming that the material has excellent price competitiveness and high efficiency compared to the existing magnetic heat material Gd ₃ SnC while replacing the use of the gas refrigerant causing the greenhouse effect.

In order to achieve the above object, the present invention provides a magnetothermal material, characterized in that:

[Formula 1]

(Gd _{1 - x} A _x ) ₃ SnC

Wherein A is La or Ce, x is a prime number and 0 <x <1.

The magnetothermal material has an antiperovskite structure, each Sn (x, y, z = 0, 0, 0), C (x, y, z in the antiperovskite structure 0.5, 0.5, 0.5) The element may have a structure in which the position of the element deviates within several degrees from a structurally stable position and is locally distorted.

Here, antiperovskite (Antiperovskite) is an ionic bond in which the structure of the cation and anion is reversed in the conventional Perovskite structure. It contains a large number of elements per unit cell, making it a very suitable material for increasing the magnetocaloric effect.

The present invention also provides

(a) preparing a synthetic raw material comprising either La or Ce and Gd, Sn and C by a melt-cooling process; And

(b) remelting-cooling the synthetic raw material obtained in step (a);

It provides a method for producing a magnetic thermal material comprising a.

The magnetocaloric material may be represented by the following Chemical Formula 1.

[Formula 1]

(Gd _{1 - x} A _x ) ₃ SnC

Where A is La or Ce, x is prime and 0 <x <1

The magnetothermal material has an antiperovskite structure, and in the antiperovskite structure, each Sn and C element is locally deformed from the structurally stable position. May have

The step (a) is preferably made through an arc melting method, and the step (b) is also preferably made through an arc melting method.

Preferably, step (a) is performed in an inert gas atmosphere, and step (b) is preferably performed in an inert gas atmosphere.

Argon, helium, or neon may be preferably used for the inert gas.

The present invention also provides

It provides a cooling system, characterized in that using a magnetic heat material represented by the formula (1).

[Formula 1]

(Gd _{1 - x} A _x ) ₃ SnC

Where A is La or Ce, x is prime and 0 <x <1

The magnetothermal material has an antiperovskite structure, and in the antiperovskite structure, each Sn and C element is locally deformed from the structurally stable position. May have

The magnetocaloric material according to the present invention has an antiperovskite structure having a mass of three times or more per unit cell, unlike a magnetothermal material of Gd metal having a conventional rhombohedral structure. By expressing the maximized magnetothermal effect, it is possible to have an excellent price competitiveness and energy efficiency compared to the reference magnetothermal material.

By using the method for producing a magnetothermal material provided in the present invention, it is possible to mass-produce a magnetothermal material having an antiperovskite structure by a simple melting and heat treatment process.

The material having the self-heating effect provided in the present invention has excellent price competitiveness and high efficiency compared to the existing magnetic heat material Gd while replacing the use of the gas refrigerant causing the greenhouse effect, and thus can be used as various cryogenic cooling materials. In addition, the temperature range of the magnetocaloric effect was controlled by controlling the element content of Gd and La or Gd and Ce in the material.

The present invention does not use a driving device for the compression and circulation of the gas refrigerant, it can be applied to the cooling device sensitive to noise and vibration.

1 is a schematic diagram of a crystal structure of (Gd _{1 - x} La _x ) ₃ SnC (0 <x <1) prepared in Example 1. FIG.
Figure 2 is an X-ray diffraction analysis of (Gd _{1 - x} La _x ) ₃ SnC (0 <x <1) prepared in Example 1.
3 is a result of measuring the susceptibility according to the temperature of (Gd _{1 - x} La _x ) ₃ SnC (0 <x <1) and Gd ₃ SnC (comparative example) prepared in Example 1.
4 is a schematic diagram of a crystal structure of (Gd _{1 - x} Ce _x ) ₃ SnC (0 <x <1) prepared in Example 2. FIG.
5 is an X-ray diffraction analysis of (Gd _{1 - x} Ce _x ) ₃ SnC (0 <x <1) prepared in Example 2. FIG.
6 is a result of measuring the susceptibility according to the temperature of (Gd _{1 - x} Ce _x ) ₃ SnC (0 <x <1) and Gd ₃ SnC (comparative example) prepared in Example 2.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail. In the following description of the present invention, detailed descriptions of related well-known configurations or functions may be omitted.

The terms or words used in the specification and claims are not to be construed as being limited to conventional or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical matters of the present invention.

The embodiments described in the specification and the configuration shown in the drawings are preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, various equivalents and modifications that can replace them at the time of the present application are There may be.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention provides a magnetothermal material, characterized in that represented by the following formula (1).

[Formula 1]

(Gd _{1 - x} A _x ) ₃ SnC

Where A is La or Ce, x is prime and 0 <x <1

The magnetothermal material has an antiperovskite structure, and in the antiperovskite structure, each Sn and C element is locally deformed from the structurally stable position. May have

Here, antiperovskite (Antiperovskite) is a ionic bond in which the structure of the cation and anion is reversed in the conventional Perovskite structure. It contains a large number of elements per unit cell, making it a very suitable material for increasing the magnetocaloric effect.

The present invention also provides

(a) preparing a synthetic raw material comprising either La or Ce and Gd, Sn and C by a melt-cooling process; And

(b) remelting-cooling the synthetic raw material obtained in step (a);

Including,

It provides a method for producing a magnetocaloric material represented by the following formula (1).

[Formula 1]

(Gd _{1 - x} A _x ) ₃ SnC

Where A is La or Ce, x is prime and 0 <x <1

The magnetocaloric material has an antiperovskite structure as shown in FIGS. 1 and 4, and each Sn and C element is structurally positioned in the antiperovskite structure. It may have a structure that is deformed locally from a stable position.

The step (a) is preferably made through an arc melting method, and the step (b) is also preferably made through an arc melting method.

Preferably, step (a) is performed in an inert gas atmosphere, and step (b) is preferably performed in an inert gas atmosphere.

Argon, helium, or neon may be preferably used for the inert gas.

The present invention also provides

It provides a cooling system, characterized in that using a magnetic heat material represented by the formula (1).

[Formula 1]

(Gd _{1 - x} A _x ) ₃ SnC

Where A is La or Ce, x is prime and 0 <x <1

The magnetothermal material has an antiperovskite structure, and in the antiperovskite structure, each Sn and C element is locally deformed from the structurally stable position. May have

Hereinafter, the present invention will be described in more detail with reference to Examples and Evaluation Examples. These examples and evaluation examples are only for explaining the present invention in more detail, and the scope of the present invention is not limited by these examples and evaluation examples according to the gist of the present invention having ordinary knowledge in the art. It is self-evident to him.

<Example 1. (Gd _1-x La _x ) ₃ Preparation of SnC (0 <x <1)>

Gd and La metal is processed to 1 g ³ , 10 g according to the x ratio of the above formula and quantified Sn (metal shot) and C (graphite piece) in proportion.

The internal pressure is fixed at 0.1 Pa in an arc melting furnace in an argon gas atmosphere where an arc beam can be generated, and then the raw materials quantified by the arc melting method are melted to mix and synthesize materials. The raw material heated to 3000 degrees or more by arc beam and molten state is solidified by naturally cooling in the Argon gas atmosphere chamber at room temperature,

The melt-solidified material is turned upside down three times inside the Arc melting furnace and re-melted-cooled with the same process and conditions as the above method. Through this, it is possible to secure a homogeneous and high purity magnetothermal material.

Evaluation Example 1. X-ray Diffraction Patterns

An X-ray diffraction pattern was measured for the magnetothermal material according to Example 1. As a result, the X-ray diffraction pattern of [FIG. 2] was obtained. As a result, the magnetothermal material was confirmed to have an Antiperovskite structure and a single phase of (Gd _{1 - x} La _x ) ₃ SnC (0 <x <1).

Evaluation Example 2 Evaluation of Magnetic Heat Characteristics

The magnetocaloric properties of the magnetocaloric materials according to Example 1 were evaluated. In order to evaluate the magnetothermal characteristics, the susceptibility according to temperature was measured, thereby obtaining the susceptibility measurement results of FIG. 3.

(Gd _{1 - x} La _x ) ₃ SnC (0 <x <1) prepared according to Example 1 exhibits a ferromagnetic property in which the susceptibility is changed at a lower temperature compared to pure Gd ₃ SnC metal. As shown in FIG. 3, the change in magnetization rate is lower than that of Gd ₃ SnC (comparative example), which is a conventionally used magnetic material, thereby securing universality and expandability as a magnetic cooling material in an even temperature range.

As a result of measuring the susceptibility of Gd ₃ SnC (comparative example), which is a conventionally used magnetothermal material, as shown in FIG. 3, (Gd _{1 - x} La _x ) ₃ SnC (0 <x <1) It was confirmed that the change of the susceptibility according to the temperature is constantly controlled.

< Example  2. ( Gd _{One - x} Ce _x ) ₃ SnC  (0 <x < 1) of  Manufacture

Gd and Ce metal is processed to 1 cm ³ , 10 g according to the x ratio of the above formula and quantified Sn (metal shot) and C (graphite piece) in proportion.

The materials are mixed and synthesized by melting the raw material quantified by the Arc melting method in an arc melting furnace in an argon gas atmosphere where an arc beam may be generated. The heated and molten raw material is solidified by natural cooling in an Argon gas atmosphere chamber at room temperature, and the melt-solidified material is re-melted and cooled by the same process and conditions as the above method by inverting three times up and down inside the Arc melting furnace. . Through this, it is possible to secure a homogeneous and high purity magnetothermal material.

< Evaluation example  3. X-ray Diffraction Patterns>

An X-ray diffraction pattern was measured for the magnetothermal material according to Example 2. As a result, the X-ray diffraction pattern of [FIG. 5] was obtained. As a result, it was confirmed that the magnetothermal material had an Antiperovskite structure and was a single phase of (Gd _{1 - x} Ce _x ) ₃ SnC (0 <x <1).

< Evaluation example  4. Magnetism  Property Evaluation>

The magnetocaloric properties of the magnetocaloric materials according to Example 2 were evaluated. In order to evaluate the magnetic heat characteristics, the susceptibility according to temperature was measured, and the susceptibility measurement results of FIG. 6 were obtained.

(Gd _{1 - x} Ce _x ) ₃ SnC (0 <x <1) prepared according to Example 2 exhibits a ferromagnetic property in which the susceptibility is changed at low temperatures compared to pure Gd ₃ SnC metal. As shown in FIG. 6, the change in magnetization rate was lowered at a lower temperature than that of Gd ₃ SnC (Comparative Example), which is a conventionally used magnetic material, thereby securing universality and expandability as a magnetic cooling material in an even temperature range.

As a result of measuring the susceptibility of Gd ₃ SnC (comparative example), which is a conventionally used magnetothermal material, as shown in FIG. 6, the value of (Gd _{1 - x} Ce _x ) ₃ SnC (0 <x <1) It was confirmed that the change of the susceptibility according to the temperature is constantly controlled.

Claims (6)

A magnetic heating material represented by the following Chemical Formula 1 and having an antiperovskite structure:
(Gd _1-x A _x ) ₃ SnC
Wherein A is La or Ce, x is a prime number and 0 <x <1.
delete (a) preparing a synthetic raw material comprising either La or Ce and Gd, Sn and C by a melt-cooling process; And
(b) remelting-cooling the synthetic raw material obtained in step (a);
A method of preparing a magnetic thermal material represented by the following Chemical Formula 1 and having an antiperovskite structure:
[Formula 1]
(Gd _1-x A _x ) ₃ SnC
Wherein A is La or Ce, x is a prime number and 0 <x <1.
The method of claim 3,
The step (a) and step (b) is a method of producing a magnetocaloric material, characterized in that each through the arc melting method (Arc melting method).
The method of claim 3,
The step (a) and step (b) is a method of producing a magnetothermal material, characterized in that each carried out in an inert gas atmosphere.
A cooling system represented by the following formula (1) and using a magnetothermal material having an antiperovskite structure:
[Formula 1]
(Gd _1-x A _x ) ₃ SnC
Wherein A is La or Ce, x is a prime number and 0 <x <1.

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