KR20160081657A - Magnetocaloric material, products including the magnetocaloric material, and method of manufacturing the magnetocaloric material - Google Patents

Abstract

The present invention relates to a magnetocaloric material comprising a substance represented by formula 1, (Mn_(1-x)Tm_x)_5PB_2, a substance represented by formula 2, Mn_5P_(1-y)A_yB_2, a substance represented by formula 3, Mn_5P_(1-z)B_(2+z), or a combination thereof, to a product comprising the magnetocaloric material, and to a manufacturing method of the magnetocaloric material. The descriptions regarding the formulas are the same as described in the specification. The magnetocaloric material of the present invention can improve a magnetocaloric effect by controlling magnetic properties.

Description

TECHNICAL FIELD [0001] The present invention relates to a magnetoresistive material, a product including the magnetoresistive material, and a method of manufacturing the magnetoresistive material,

A magnetic thermal material, a product including the magnetic thermal material, and a method of manufacturing the magnetic thermal material.

The gas compression type cooling system used in the present cooling system uses gas refrigerant causing the greenhouse effect and reaches the limit of the cooling efficiency. Therefore, there is an increasing demand for development of an energy efficient and environmentally friendly cooling system. Solid state cooling systems are being studied as a substitute for gas compression cooling systems. Among them, magnetic refrigeration using a magnetocaloric effect due to magnetic phase transition of a magnetic material is attracting attention as a high efficiency, environmentally friendly solid cooling technique.

It is important to develop a high-performance magnetorheological material and its efficient manufacturing method in self-cooling technology. Magnetic entropy change (ΔS _M ), magnetic phase transition temperature (Tc), high thermal conductivity, high electrical resistance, chemical and mechanical stability, environmentally friendly Gender, low cost, and mass production potential are factors to be considered in the development of magnetic thermal materials. Gd ₅ (Ge, Si) ₄ (KA Gchneider et al .), La (Fe, Si) ₁₃ (O. Gutfleisch et al . ) Is known as a rare earth element-containing material.

The rare earth element contained in the existing magnetic thermal material is not smoothly supplied and when the first order magnetic phase transition is exhibited, a thermal / magnetic hysteresis phenomenon occurs and the thermal cycle of the self cooling system The cycle may be limited.

One embodiment provides a magnetic thermal material capable of controlling the magnetic properties to improve the magnetic thermal effect.

Another embodiment provides a product comprising the magnetorheological material.

Another embodiment provides a method of manufacturing a magnetic thermal material capable of controlling the magnetic properties to improve the magnetic thermal effect.

According to one embodiment, there is provided a magnetorheological material comprising a substance represented by the following general formula (1), a substance represented by the following general formula (2), a substance represented by the following general formula (3), or a combination thereof.

[Formula 1]

(Mn _{1 - x} Tm _x ) ₅ PB ₂

In the general formula 1,

Tm is at least one selected from transition metal elements,

0.02? X? 0.04.

[Formula 2]

Mn ₅ P _{1 - y} A _y B ₂

In the general formula 2,

A is at least one selected from a metalloid element and a nonmetal element,

0.1? Y? 0.3.

[Formula 3]

Mn ₅ P _{1 - z} B _{2 + z}

In the general formula 3,

0 &lt; z < 1.

The Tm may be at least one selected from Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn.

The A may be at least one selected from Si, As, Ge, and S.

Z may satisfy 0.075? Z < 1.

Z may satisfy 0.1? Z <1.

The magnetic thermal material may be represented by the following general formula (1a).

[Formula 1a]

(Mn _{1 - x} Fe _x ) ₅ PB ₂

In the general formula (1a)

0.02? X? 0.04.

The magnetic thermal material may be represented by the following Formula 2a.

[Formula 2a]

Mn ₅ P _{1 - y} Si _y B ₂

In the general formula 2a,

0.1? Y? 0.3.

The particle size of the magnetic thermal material may be 1 nm to 100 탆.

According to another embodiment, there is provided a product comprising the above-mentioned magnetically-heating substance.

The article may comprise two or more magnetic thermal materials.

The product may include a magnetic cooling device, a magnetic heat generator, a magnetic heat pump, and an electromagnetic wave shielding agent.

According to another embodiment, there is provided a method for producing a magnetic recording medium, comprising the steps of: obtaining a raw material mixture; and heat-treating the raw material mixture, wherein the produced magnetic thermal material comprises the substance represented by Formula 1, A material represented by the general formula (3), or a combination thereof.

The heat treatment may be performed at a temperature of 800 ° C to 1,000 ° C.

The heat treatment may be conducted three times or more.

The heat treatment may be conducted in an oxygen-free atmosphere.

The thermal and magnetic hysteresis of the magnetic thermal material can be reduced to improve the efficiency of the thermal process.

1 is an X-ray diffraction analysis graph of the magnetic thermal material obtained in Examples 1 and 2 and Comparative Examples 1 and 2,
2 is an X-ray diffraction analysis graph of the magnetic thermal material obtained in Examples 3 to 5 and Comparative Examples 3 and 4,
3 is an X-ray diffraction analysis graph of the magnetic thermal material obtained in Examples 6 to 10 and Comparative Example 6,
4 is a graph comparing the magnetization curves of the magnetic thermal materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2 according to the temperature,
5 is a graph comparing the magnetization curves of the magnetic thermal materials obtained in Examples 3 to 5 and Comparative Examples 3 and 4 according to the temperature,
6 is a graph comparing the magnetization curves of the magnetic thermal materials obtained in Examples 6 to 10 and Comparative Example 6 with temperature,
7 is a graph showing the magnetic phase transition temperatures of the magnetic thermal materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2,
8 is a graph showing the magnetic phase transition temperatures of the magnetic thermal materials obtained in Examples 3 to 5 and Comparative Examples 3 to 5,
9 is a graph showing the magnetic phase transition temperatures of the magnetic thermal materials obtained in Examples 6 to 10 and Comparative Example 6,
10 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 1. FIG.
11 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 2,
12 is a graph showing a magnetization curve according to a magnetic field of the magnetic thermal material obtained in Comparative Example 1,
13 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Comparative Example 2. FIG.
14 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 3,
15 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 4,
16 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 5,
17 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Comparative Example 3,
18 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 10,
19 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Comparative Example 6,
20 is a graph showing magnetic entropy changes of the magnetic thermal materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2,
21 is a graph showing magnetic entropy changes of the magnetic thermal materials obtained in Examples 3 to 5 and Comparative Examples 3 to 5,
22 is a graph showing magnetic entropy changes of the magnetic thermal materials obtained in Examples 6 to 10 and Comparative Example 6. Fig.

Hereinafter, exemplary embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Hereinafter, the magnetic thermal substance according to one embodiment will be described.

The magnetocaloric material is a material capable of generating a magnetic heat effect by magnetic phase transition, and the magnetic thermal material according to one embodiment is a material represented by the following general formula 1, A substance represented by the following general formula (3), or a combination thereof.

[Formula 1]

(Mn _{1 - x} Tm _x ) ₅ PB ₂

In the general formula 1,

Tm is at least one selected from transition metal elements,

0.02? X? 0.04.

[Formula 2]

Mn ₅ P _{1 - y} A _y B ₂

In the general formula 2,

A is at least one selected from a metalloid element and a nonmetal element,

0.1? Y? 0.3.

[Formula 3]

Mn ₅ P _{1 - z} B _{2 + z}

In the general formula 3,

0 &lt; z < 1.

The magnetic thermal material according to one embodiment includes Mn, P, and B as basic constituent elements, and limits the amounts of Mn, P, and B to a predetermined range or substitutes a part of Mn, P, and B with other elements It is a Mn ₅ PB ₂ system magnetic thermal material.

For example, the magnetoresistive material may be formed by replacing a part of Mn, which is a magnetic element, with a transition metal.

Examples of the transition metal include, but are not limited to, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn. It is not.

The substitution amount of the transition metal represented by x in the general formula 1 is selected in a range of 0.02? X? 0.04, for example, x may be about 0.02, about 0.03, or about 0.04, but is not limited thereto.

As described above, the magnetic thermal material according to an example can change the magnetic interaction by substituting a part of Mn, which is a magnetic element, with a transition metal element. Since the magnetic moment of the transition metal element is relatively larger than that of Mn, it is possible to increase the entropy change (-ΔS _M ) by replacing a part of Mn with the transition metal element, Can be improved.

The magnetic thermal material can be represented by the following general formula (1a).

[Formula 1a]

(Mn _{1 - x} Fe _x ) ₅ PB ₂

In the general formula (1a)

0.02? X? 0.04.

In another example, the magnetic thermal substance may be a form in which a part of P, which is a non-magnetic element, is substituted with a metalloid element or a non-metal element.

The substitutional metal element or nonmetal element may be one or more than two, and examples of the non-limiting examples of the quasi-metal element or the non-metal element include Si, As, Ge, and S, but are not limited thereto.

In the general formula 2, the substitution amount of the quasi-metallic element or the non-metallic element represented by y is selected in a range of 0.1? Y? 0.3, for example, the y may be about 0.1, about 0.2, or about 0.3.

As described above, the magnetic thermal material according to another example can change the magnetic interaction by replacing a part of P with a quasi-metallic element or a non-metallic element. Substituting the non-magnetic element P with a sub-metallic element or a non-metallic element decreases the value of the magnetic phase transition temperature (Tc), thereby reducing the magnetic hysteresis curve. Further, by increasing the change in entropy (-ΔS _M) it is possible to improve the magnetic characteristics of the magnetic thermal cooling material.

The magnetic thermal material can be represented by the following general formula (2a).

[Formula 2a]

Mn ₅ P _{1 - y} Si _y B ₂

In the general formula 2a,

0.1? Y? 0.3.

In another example, the magnetic thermal material may be in the form of limiting the amounts of Mn, P, and B, which are basic constituents, to a predetermined range, which is expressed by the general formula 3. The magnetocrystalline material represented by the general formula 3 reduces the amount of P in the Mn ₅ PB ₂ structure and increases the amount of B to correspond to the decrease amount of P.

In the above general formula (3), the amount of decrease of P represented by z (that is, the amount of increase of B) is selected in the range of 0 <z <1, for example, z satisfies 0.075? Z < But is not limited thereto.

As described above, the magnetic thermal material according to another example can improve the self-cooling property of the magnetic thermal material by increasing the entropy change (-ΔS _M ) by replacing part of P with B.

As described above, the magnetocrystalline material can be prepared by limiting the amount of Mn, P, and B, which are basic constituents, to a predetermined range, or by replacing Mn ₅ PB ₂ by a method of replacing a part of Mn, P, And the magnetic properties can be controlled by changing the magnetic interaction by replacing the Mn ₅ PB ₂ system with a non-chemical equivalent.

The magnetic thermal substance represented by any one of the general formulas 1 to 3 may have a reduced magnetic hysteresis curve as compared with Mn ₅ PB ₂ .

In addition, the magnetic thermal material expressed by any one of the general formulas 1 to 3 has an increased entropy change and thermal process efficiency as compared with Mn ₅ PB _2, and the cooling characteristics can be improved. Therefore, when the magnetic heating material is applied to a cooling device such as a refrigerator or an air conditioner, energy loss can be reduced and high efficiency can be realized.

The magnetic thermal material may use two or more kinds of magnetic thermal materials having different compositions. For example, a magnetic thermal substance having a magnetic phase transition temperature of about 310 K, a magnetic thermal substance having a magnetic phase transition temperature of about 320 K, and a magnetic thermal substance having a magnetic phase transition temperature of about 330 K, The operating temperature range can be greatly widened.

The magnetic thermal material may be contained in the form of particles, and the particles may be, for example, microcrystalline particles. The average particle size of the magnetic thermal material may be, for example, about 1 nm to 100 탆. By having an average particle diameter in the above range, the generation of cracks can be prevented or alleviated, so that the self-cooling efficiency and the life characteristics can be further improved. Within this range, it may have an average particle diameter of about 10 nm to 100 mu m, and within this range, it may have an average particle diameter of about 100 nm to 5 mu m.

The magnetic thermal material may be formed and / or processed into various shapes to produce various products requiring magnetic heat effect. The product may include, but is not limited to, a self-cooling device, a magnetic heat generator, a magnetic heat pump, and an electromagnetic wave shielding agent. At this time, by using two or more types of magnetic thermal materials as described above, it is possible to broaden the application temperature range by enlarging the temperature range in which magnetism can be seen.

Hereinafter, a method of manufacturing a magnetic thermal material according to one embodiment will be described.

A method of manufacturing a magnetorheological material according to an embodiment includes the steps of obtaining a raw material mixture and heat treating the raw material mixture.

The raw material mixture contains manganese or a precursor thereof, iron or a precursor thereof, and phosphorus or a precursor thereof as a basic component, and the transition metal element, the metalloid element, the nonmetal element, or the precursor thereof may be added according to the intended composition have. The raw materials can be mixed, for example, in the form of powders or flakes, and the precursors can be mixed with other additives such as hydroxides, alkoxides, citrates, acetates, carbonates, (meth) acrylates, nitrates, , Halide, sulfonate, phosphate or hydrate form thereof.

The reducing agent may be mixed together. The reducing agent may include at least one selected from, for example, Group I elements, Group II elements, Group III elements, and combinations thereof. The Group I element may be, for example, lithium (Li), sodium (Na), potassium (K) or a combination thereof. The Group II element may be, for example, beryllium (Be), magnesium (Mg) (Sr), barium (Ba), or a combination thereof, and the Group III element may be aluminum (Al), for example.

The reducing agent is uniformly dispersed in the mixture and the oxidation reaction of the reducing agent is an exothermic reaction so that the mixture is heated uniformly so that the reaction between the substances contained in the mixture can be uniformly performed as a whole . Also, the oxide formed by oxidizing the reducing agent is formed between the generated magnetic thermal materials, and the material formed by oxidizing the reducing agent and the generated magnetic thermal material do not react with each other. Thus, the material formed by oxidizing the reducing agent can control the growth of the magnetic thermal material, thereby controlling the particle size and uniformity of the magnetic thermal material.

The mixing may be, for example, a ball mill process, an attrition mill process, a jet mill process, a spike mill process, or a combination thereof, but is not limited thereto.

The raw material mixture may be prepared as a compressed product in a compressed form by applying a predetermined pressure.

The heat treatment of the mixture may be performed by, for example, conventional heating, microwave heating, induction heating, spark plasma sintering, or the like, for example, at a temperature of about 800 to 1,000 DEG C For about 5 to 100 hours.

The heat treatment may be performed a plurality of times, for example, three heat treatments may be performed at 800 to 1,000 DEG C for about 5 to 100 hours.

The heat treatment may be performed in an oxygen-free atmosphere, and may be performed in an inert atmosphere such as argon gas, a reducing atmosphere such as hydrogen gas, or a vacuum atmosphere.

Examples and comparative examples of the present invention will be described below. However, the following examples are only examples of the present invention, and the present invention is not limited by the following examples.

Magnetic column  Manufacture of materials

Example  1 and 2, Comparative Example  1 and 2

Polycrystalline (Mn _{1 - x} Fe _x ) ₅ PB ₂ is synthesized by the solid synthesis method. To prevent oxidation of the material, all synthesis proceed in a glove box filled with argon. The Mn, Fe, P, and B powders, which are materials, are weighed in different amounts depending on the composition to be obtained. Then put in a bowl and mix well for about 30 minutes. Mix the powder with a metal frame to make a pellet and put it in a quartz tube. Vacuum the quartz using a vacuum pump and melt the end. The sample sealed in quartz is heated in an electric furnace at a rate of 100 ° C / h, reacted at 800 ° C for 24 hours, and cooled. The sample was taken out of the quartz tube, and the sample was finely ground with a mortar for 30 minutes. The pellet was made using a metal frame. The sample was vacuum-sealed in a quartz tube using a vacuum pump, and the quartz- Deg.] C / h, reacted at 900 [deg.] C for 48 hours, and cooled again. The sample was removed from the quartz tube again, and the sample was finely ground with a mortar for 30 minutes. The pellet was formed using a metal frame, and the sample was vacuum sealed in a quartz tube using a vacuum pump. At a rate of 100 占 폚 / h, reacted at 950 占 폚 for 48 hours, and then cooled again to obtain a magnetic thermal substance having the composition shown in Table 1 below.

(Mn _{1 - x} Fe _x ) ₅ PB ₂ Example 1 X = 0.02 Example 2 X = 0.04 Comparative Example 1 X = 0.08 Comparative Example 2 X = 0

Example  3 to 5, Comparative Example  3 to 5

Polycrystalline Mn ₅ (P _{1 - x} Si _x ) B ₂ is synthesized by the solid synthesis method. To prevent oxidation of the material, all synthesis proceed in a glove box filled with argon. The Mn, P, Si, and B powders, which are materials, are weighed in different amounts depending on the composition to be obtained. Then put in a bowl and mix well for about 30 minutes. Mix the powder with a metal frame to make a pellet and put it in a quartz tube. Vacuum the quartz using a vacuum pump and melt the end. The sample sealed in quartz is heated in an electric furnace at a rate of 100 ° C / h, reacted at 800 ° C for 24 hours, and cooled. The sample was taken out of the quartz tube, and the sample was finely ground with a mortar for 30 minutes. The pellet was made using a metal frame. The sample was vacuum-sealed in a quartz tube using a vacuum pump, and the quartz- Deg.] C / h, reacted at 900 [deg.] C for 48 hours, and cooled again. The sample was removed from the quartz tube again, and the sample was finely ground with a mortar for 30 minutes. The pellet was formed using a metal frame, and the sample was vacuum sealed in a quartz tube using a vacuum pump. At 100 ° C / h, reacted at 930 ° C for 48 hours, and cooled again to obtain a magnetic thermal material having the composition shown in Table 2 below.

Mn ₅ (P _{1 - x} Si _x ) B ₂ Example 3 x = 0.1 Example 4 x = 0.2 Example 5 x = 0.3 Comparative Example 3 x = 0.4 Comparative Example 4 x = 0.5 Comparative Example 5 x = 0

Example  6 to 10, Comparative Example  6

It synthesizes B _{x 2 -x} the solid _{synthesis-polycrystalline} Mn ₅ P _1. To prevent oxidation of the material, all synthesis proceed in a glove box filled with argon. The Mn, P and B powders, which are the materials, are weighed in different amounts depending on the composition to be obtained. Then put in a bowl and mix well for about 30 minutes. Mix the powder with a metal frame to make a pellet and put it in a quartz tube. Vacuum the quartz using a vacuum pump and melt the end. The sample sealed in quartz is heated in an electric furnace at a rate of 100 ° C / h for 12 hours at 300 ° C and for 48 hours at 700 ° C, followed by cooling. The sample was taken out of the quartz tube, and the sample was finely ground with a mortar for 30 minutes. The pellet was made using a metal frame. The sample was vacuum-sealed in a quartz tube using a vacuum pump, and the quartz- Lt; 0 &gt; C / h, reacted at 800 DEG C for 48 hours, and cooled again. The sample was removed from the quartz tube again, and the sample was finely ground with a mortar for 30 minutes. The pellet was formed using a metal frame, and the sample was vacuum sealed in a quartz tube using a vacuum pump. At a rate of 100 占 폚 / h, reacted at 900 占 폚 for 48 hours, and cooled again to obtain a magnetic thermal substance having the composition shown in Table 3 below.

_{Mn 5 P 1 - x B 2} -x Example 6 x = 0.025 Example 7 x = 0.05 Example 8 x = 0.075 Example 9 x = 0.1 Example 10 x = 0.2 Comparative Example 6 x = 0

evaluation

Rating 1

The crystal structures of the magnetic thermal materials obtained in Examples 1 to 10 and Comparative Examples 1 to 6 are confirmed by X-ray diffraction analysis.

The results are shown in Figures 1-3.

Fig. 1 is an X-ray diffraction analysis graph of the magnetic thermal material obtained in Examples 1 and 2 and Comparative Examples 1 and 2, Fig. 2 is a graph showing X-ray diffraction patterns of the magnetoresistive materials obtained in Examples 3 to 5 and Comparative Examples 3 and 4 Ray diffraction analysis graph, and FIG. 3 is an X-ray diffraction analysis graph of the magnetic thermal material obtained in Examples 6 to 10 and Comparative Example 6. FIG.

Referring to FIGS. 1 to 3, it can be seen that the magnetic thermal materials obtained in Examples 1 to 10 and Comparative Examples 1 to 6 have substantially the same crystal structure, and no other impurity phase is seen.

Rating 2

The change in magnetization curve according to the temperature of the magnetic thermal material obtained in Examples 1 to 10 and Comparative Examples 1 to 6 is evaluated.

The results are shown in Figures 4-6.

FIG. 4 is a graph comparing the magnetization curves of the magnetic thermal materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2 with temperature, FIG. 5 is a graph comparing the magnetization curves of the magnetoresistive materials obtained in Examples 3 and 5, FIG. 6 is a graph comparing the magnetization curves of the magnetic thermal materials obtained in Examples 6 to 10 and Comparative Example 6 according to the temperature. FIG.

4 to 6, the temperature at the point showing the maximum slope can be defined as the magnetic phase transition temperature.

Referring to FIG. 4, it can be seen that the magnetization degree of the magnetoresistive material (x = 0.04) according to Example 2 is the highest at around the magnetic phase transition temperature. Referring to FIG. 5, it can be seen that the magnetization degree of the magnetic thermal substance (x = 0.3) according to Example 5 is the highest at around the magnetic phase transition temperature. Referring to FIG. 6, it can be seen that the magnetization degree of the magnetic thermal substance (x = 0.1) according to Example 9 is the highest in the vicinity of the magnetic phase transition temperature.

Rating 3

The magnetic phase transition temperature trends of the magnetic thermal materials obtained in Examples 1 to 10 and Comparative Examples 1 to 6 are evaluated.

The results are shown in Figs. 7-9.

FIG. 7 is a graph showing the magnetic phase transition temperatures of the magnetic thermal materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2, FIG. 8 is a graph showing the magnetic phase transition of the magnetic thermal material obtained in Examples 3 to 5 and Comparative Examples 3 to 5 FIG. 9 is a graph showing the magnetic phase transition temperatures of the magnetic thermal materials obtained in Examples 6 to 10 and Comparative Example 6. FIG.

Referring to FIG. 7, it can be seen that the magnetic phase transition temperature increases as manganese is replaced with iron. Referring to FIG. 8, it can be seen that the magnetic phase transition temperature is increased by replacing phosphorus with silicon. Referring to FIG. 9, it can be seen that the phase transition temperature does not vary greatly depending on the amount of the boron additive. Also, referring to FIG. 9, it can be seen that the magnetic hysteresis curve decreases greatly at x = 0.1, which means that the latent heat required for the heat process is lowered, thereby increasing the efficiency of the self-cooling effect.

Rating 4

The change in magnetization curve according to the magnetic field of the magnetic thermal material obtained in Examples 1 to 10 and Comparative Examples 1 to 6 is evaluated.

The results are shown in Figures 10-19.

FIG. 10 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 1, FIG. 11 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 2, FIG. 13 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Comparative Example 2, and FIG. 14 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 3. FIG. 15 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 4. FIG. 16 is a graph showing a magnetization curve according to the magnetic field of the magnetic thermal material obtained in Example 5. FIG. 17 is a graph showing the magnetization curve according to the magnetic field of the magnetic thermal material obtained in Comparative Example 3, and FIG. 18 is a graph showing the magnetization curve according to Example 10 And that shows the magnetization curve of the magnetic field of the magnetic material standing column obtained graph, Figure 19 is a graph showing the magnetization curve of the magnetic field of the magnetic column material obtained in Comparative Example 6.

Rating 5

The magnetic entropy changes of the magnetic thermal materials obtained in Examples 1 to 10 and Comparative Examples 1 to 6 are evaluated. The magnetic entropy change is calculated using the McWell relational expression through the change in magnetization according to evaluation 4.

The results are shown in Figures 20-22.

FIG. 20 is a graph showing magnetic entropy changes of the magnetic thermal materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2, FIG. 21 is a graph showing the magnetic enthalpy change of the magnetic thermal material obtained in Examples 3 to 5 and Comparative Examples 3 to 5 FIG. 22 is a graph showing magnetic entropy changes of the magnetic thermal materials obtained in Examples 6 to 10 and Comparative Example 6. FIG.

Referring to FIG. 20, the magnetic thermal material obtained in Examples 1 and 2 can clearly confirm a change in magnetic entropy as compared with the magnetic thermal materials obtained in Comparative Examples 1 and 2. In particular, in Example 2 (x = 0.04) It can be seen that the entropy change of the magnetic thermal material according to Comparative Example 2 (x = 0) before the replacement was increased by about 10% as compared with the entropy change of the magnetic thermal substance.

Referring to FIG. 21, the magnetic thermal materials obtained in Examples 3 to 5 can clearly confirm a change in magnetic entropy as compared with the magnetic thermal materials obtained in Comparative Examples 3 to 5, and in particular, in Example 5 (x = 0.3) It can be seen that the entropy change of the magnetic thermal substance according to Comparative Example 5 (x = 0) before the replacement was increased by about 22% as compared with the entropy change of the magnetic thermal substance.

Referring to FIG. 22, the magnetic thermal material obtained in Examples 6 to 10 can clearly confirm a change in magnetic entropy as compared with the magnetic thermal material obtained in Comparative Example 6, It can be seen that the entropy change of the thermal material is increased by about 18% compared with the entropy change of the magnetic thermal substance according to Comparative Example 6 (x = 0) before substitution.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And it goes without saying that the invention belongs to the scope of the invention.

Claims (16)

A magnetoresistive material comprising a material represented by the following general formula (1), a material represented by the following general formula (2), a material represented by the following general formula (3)
[Formula 1]
(Mn _{1 - x} Tm _x ) ₅ PB ₂
In the general formula 1,
Tm is at least one selected from transition metal elements,
0.02? X? 0.04.
[Formula 2]
Mn ₅ P _{1 - y} A _y B ₂
In the general formula 2,
A is at least one selected from a metalloid element and a nonmetal element,
0.1? Y? 0.3.
[Formula 3]
Mn ₅ P _{1 - z} B _{2 + z}
In the general formula 3,
0 &lt; z < 1. The method of claim 1,
Wherein the Tm is at least one selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn. The method of claim 1,
Wherein A is at least one selected from Si, As, Ge, and S. The method of claim 1,
And z satisfies 0.075? Z < 1. The method of claim 1,
Z is a magnetic thermal substance satisfying 0.1? Z < 1. The method of claim 1,
Magnetic thermal material represented by the following formula 1a:
[Formula 1a]
(Mn _{1 - x} Fe _x ) ₅ PB ₂
In the general formula (1a)
0.02? X? 0.04. The method of claim 1,
Magnetic thermal material represented by the following formula 2a:
[Formula 2a]
Mn ₅ P _{1 - y} Si _y B ₂
In the general formula 2a,
0.1? Y? 0.3. The method of claim 1,
Wherein the magnetic thermal material has a particle size of 1 nm to 100 μm. 9. An article comprising a magnetorheological material according to any one of claims 1 to 8. The method of claim 9,
A product comprising two or more magnetic thermal materials. The method of claim 9,
Magnetic cooling apparatus, magnetic heat generator, magnetic heat pump, and electromagnetic shielding agent. A method of manufacturing a magnetic thermal material,
Obtaining a raw material mixture; And
Heat treating the raw material mixture
Lt; / RTI &gt;
Wherein the magnetic thermal material comprises a substance represented by the following Formula 1, a substance represented by the following Formula 2, a substance represented by the following Formula 3, or a combination thereof:
[Formula 1]
(Mn _{1 - x} Tm _x ) ₅ PB ₂
In the general formula 1,
Tm is at least one selected from transition metal elements,
0.02? X? 0.04.
[Formula 2]
Mn ₅ P _{1 - y} A _y B ₂
In the general formula 2,
A is at least one selected from a metalloid element and a nonmetal element,
0.1? Y? 0.3.
[Formula 3]
Mn ₅ P _{1 - z} B _{2 + z}
In the general formula 3,
0 < z < 1. The method of claim 12,
Wherein the heat treatment is performed at a temperature of 800 ° C to 1,000 ° C. The method of claim 13,
Wherein the heat treatment is performed three times or more. The method of claim 12,
Wherein the heat treatment is performed in an oxygen-free atmosphere. The method of claim 12,
Wherein the magnetic thermal material has a particle size of 1 nm to 100 탆.

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