阅读说明：本技术 一种Bi取代的Mn缺位Mn2Sb基合金及其制备方法和应用 (Bi-substituted Mn-vacancy Mn2Sb-based alloy, and preparation method and application thereof ) 是由 马胜灿 张智硕 罗小华 张玉希 曾海 余广 于 2020-07-01 设计创作，主要内容包括：本发明涉及磁性相变材料技术领域,本发明公开了一种Bi取代的Mn缺位Mn<Sub>2</Sub>Sb基合金及其制备方法和应用,Bi取代的Mn缺位Mn<Sub>2</Sub>Sb基合金的化学式为：Mn<Sub>2-y</Sub>Sb<Sub>1-x</Sub>Bi<Sub>x</Sub>,其中y为Mn原子的缺位量,x表示Bi对Sb的取代量,0<y<1,0<x≤0.4；本发明先通过过渡元素缺位来调控并实现一级磁相变,再通过掺杂或元素取代的方法制备得到了Bi取代的Mn缺位Mn<Sub>2</Sub>Sb基合金,在合金中调控实现一级磁弹性相变并获得丰富的磁功能性质,Bi取代的Mn缺位Mn<Sub>2</Sub>Sb基合金能够广泛应用于磁制冷、磁存储、磁传感、能量捕获和能量交换等多个领域,且制备方法简单方便、能源消耗少,制备成本低,适合工业化生产。(The invention relates to the technical field of magnetic phase-change materials, and discloses Bi-substituted Mn lacking Mn 2 Sb-based alloy, preparation method and application thereof, Bi-substituted Mn-deficient Mn 2 The chemical formula of the Sb-based alloy is as follows: mn 2‑y Sb 1‑x Bi x Wherein y is the vacancy of Mn atom, x represents the substitution of Bi for Sb, 0<y<1，0<x is less than or equal to 0.4; the invention firstly realizes the first-order magnetic phase change through the regulation and control of transition element vacancy, and then prepares the Bi-substituted Mn-vacancy Mn through the doping or element substitution method 2 Sb-based alloyThe first-order magnetoelastic phase change is realized and rich magnetic functional properties are obtained by regulating and controlling in the alloy, and Bi replaces Mn with a lack of Mn 2 The Sb-based alloy can be widely applied to a plurality of fields of magnetic refrigeration, magnetic storage, magnetic sensing, energy capture, energy exchange and the like, and the preparation method is simple and convenient, low in energy consumption and low in preparation cost, and is suitable for industrial production.)

1. Bi-substituted Mn-vacancy Mn₂Sb-based alloy characterized in that the alloy has the chemical formula Mn_2-ySb_1-xBi_x；

Wherein y is the vacancy amount of Mn atoms, x represents the substitution amount of Bi for Sb, y is more than 0 and less than 1, and x is more than 0 and less than or equal to 0.4.

2. A Bi-substituted Mn-deficient Mn according to claim 1₂The preparation method of the Sb-based alloy is characterized by comprising the following steps of:

the method comprises the following steps: weighing Mn, Sb and Bi raw materials according to a stoichiometric ratio;

step two: preparing the raw materials into Bi-doped Mn by adopting an electric arc melting method, induction melting, melt rapid quenching, spark plasma sintering, microwave sintering, directional solidification or magnetron sputtering method₂Sb-based vacancy alloy, and then carrying out heat treatment to obtain Bi-substituted Mn₂Sb-based vacancy alloys.

3. A Bi-substituted Mn-deficient Mn according to claim 1₂The preparation method of the Sb-based alloy is characterized in that in the step one, the purities of Mn, Sb and Bi metal simple substances are all over 99.99%.

4. A Bi-substituted Mn-deficient Mn according to claim 2₂The preparation method of the Sb-based alloy is characterized in that when an arc melting method is adopted, Mn is added in the second step₂The heat treatment homogenization annealing temperature of the Sb-based vacancy alloy is 500-1000 ℃, and the annealing time is 48-200 h.

5. A Bi-substituted Mn-deficient Mn according to claim 2₂The preparation method of the Sb-based alloy is characterized in that when an arc melting method is adopted, Mn is added in the second step₂The heat treatment homogenization annealing temperature of the Sb-based vacancy alloy is 500-800 ℃, and the annealing time is 48-120 h.

6. A Bi-substituted Mn-deficient Mn according to claim 1₂Sb-based alloy characterized in that said Bi-doped Mn₂The Sb-based vacancy alloy is a magnetic phase change material with first-order magnetoelastic phase change, and the Bi-doped Mn₂The neighborhood of the phase transition of the Sb-based vacancy alloy material is accompanied by magnetocaloric reaction,Giant magnetoresistance, magnetostriction, thermal expansion.

7. A Bi-substituted Mn-deficient Mn according to claim 1₂The Sb-based alloy is applied to the preparation of high-density magnetic memory devices, solid refrigeration, giant magnetoresistance devices and magnetic drivers.

Technical Field

The invention relates to the technical field of magnetic phase-change materials, in particular to Bi-substituted Mn lacking Mn₂Sb-based alloy, and a preparation method and application thereof.

Background

In recent years, multifunctional properties caused by abundant physical behaviors near the phase transformation point of the first-order magnetic phase transformation Mn-based alloy are becoming hot spots and key points in the application and basic research fields. But compared with Ni-Mn-based shape memory alloys with magnetic structure phase change, the magnetoelastic phase change alloy Mn with low cost and without easily-oxidized rare earth elements₂Sb-based alloys have attracted a great deal of attention.

For Mn₂For the Sb alloy, the positive 2:1 alloy has no first-order phase transition. Numerous studies have found that Mn is a positive constituent₂The magnetic structure of the Sb alloy is that two different Mn atoms are arranged in a stacking mode of Mn I-2 Mn II-Mn I along a c axis, adjacent Mn I-Mn II atoms are arranged in parallel, and the alloy shows ferrimagnetism. The reversal of the magnetic structure is realized by the substitution of transition group elements such as V, Cr, Co, Cu and the like for Mn bits or the substitution of main group elements such as Sn, Ge and the like for Sb bits, so that the transition group elements are arranged in an anti-parallel manner, the anti-ferromagnetic state is obtained, and the first-order magnetoelastic phase change from ferrimagnetism to anti-ferromagnetic is realized. Thus, Mn in the positive fraction₂The regulation and control of the Sb alloy to realize the first-order magnetoelastic phase change are always the most important step for obtaining excellent magnetic functional properties subsequently.

Disclosure of Invention

Aiming at the technical defects, the invention provides Bi-substituted Mn with a deficient Mn position₂The Sb-based alloy is prepared by firstly regulating and controlling the primary magnetic phase change through transition element vacancy and then preparing Bi-substituted Mn-vacancy Mn through a doping or element substitution method, and a preparation method and application thereof₂Sb-based alloy effectively broadens Mn₂The problems of the first-order magnetoelastic phase change and excellent magnetic functional property research and practical application in the Sb-based alloy, and Mn is absent in Bi substituted Mn₂The Sb ferrimagnetic material has excellent magnetocaloric effect, magnetoresistance effect and magnetostriction.

The first purpose of the invention is to provide Bi-substituted Mn lacking Mn₂An Sb-based alloy having the chemical formula: mn_{2- y}Sb_1-xBi_xWherein y is the vacancy of Mn atom, x represents the substitution of Bi for Sb, 0<y<1，0<x≤0.4。

It is a second object of the present invention to provide a Bi-substituted Mn-deficient Mn having wide-temperature-region large magnetocaloric effect, giant magnetoresistance and magnetostriction effect₂The preparation method of the Sb-based alloy comprises the following steps:

the method comprises the following steps: weighing Mn, Sb and Bi raw materials according to a stoichiometric ratio;

step two: preparing the raw materials into Bi-doped Mn by adopting an electric arc melting method, induction melting, melt rapid quenching, spark plasma sintering, microwave sintering, directional solidification or magnetron sputtering method₂Sb-based vacancy alloy, and then carrying out heat treatment to obtain Bi-substituted Mn₂Sb-based vacancy alloys.

Preferably, the purity of the Mn, Sb and Bi metal simple substances is more than 99.99%.

Preferably, when the arc melting method is adopted, Mn in the second step₂The heat treatment homogenization annealing temperature of the Sb-based vacancy alloy is 500-1000 ℃, and the annealing time is 48-200 h.

Preferably, when the arc melting method is adopted, Mn in the second step₂The heat treatment homogenization annealing temperature of the Sb-based vacancy alloy is 500-800 ℃, and the annealing time is 48-120 h.

Preferably, the Bi-doped Mn₂The Sb-based vacancy alloy is a magnetic phase change material with first-order magnetoelastic phase change, and the Bi-doped Mn₂The phase change vicinity of the Sb-based vacancy alloy material is accompanied by the physical properties of magnetocaloric property, giant magnetoresistance, magnetostriction and thermal expansion.

It is a third object of the present invention to provide the above-mentioned Bi-substituted Mn-deficient Mn having excellent magnetic functional properties such as wide-temperature-region large magnetocaloric effect, giant magnetoresistance and magnetostriction₂New use of Sb-based alloys;

the method specifically comprises the following steps: mn deficiency Mn₂The application of Sb-based alloy in the field of magnetic drivers;

mn deficiency Mn₂The application of Sb-based alloy in the field of magnetic sensitive elements;

mn deficiency Mn₂The application of Sb-based alloy in the field of giant magnetoresistance devices;

mn deficiency Mn₂The application of Sb-based alloy in the field of solid-state refrigeration;

mn deficiency Mn₂The application of Sb-based alloy in the fields of robots and artificial intelligence;

mn deficiency Mn₂The application of the Sb-based alloy in the field of energy capture and storage;

compared with the prior art, the invention has the beneficial effects that:

1) the invention mainly replaces Mn with Mn-deficient Mn through main group large-radius atoms Bi₂Sb-base alloy, designing alloy components to obtain Mn with first-order magnetoelastic phase change, and preparing Mn lacking Mn₂The Sb-based alloy is adjusted and controlled in the content of Bi element to enable adjacent magnetic moments which are arranged in parallel to be arranged in an antiparallel manner, so that the first-order magnetoelastic phase transition from ferrimagnetism to antiferromagnetic driven by temperature and a magnetic field is realized, and finally excellent magnetic functional properties such as wide-temperature-range large magnetothermal effect, giant magnetoresistance and magnetostrain effect are obtained.

2) Bi substituted Mn lacking Mn prepared by the invention₂The series of alloys prepared by the invention has abundant magnetic functional properties such as wide-temperature-region large magnetocaloric effect, giant magnetoresistance effect, magnetostriction effect and the like due to the fact that the series of alloys generate primary magnetoelastic phase transition from ferromagnetism to antiferromagnetism, so that the research range of the alloys can be widened, the cost can be greatly reduced in the application process, and the series of alloys are expected to be applied to the fields such as magnetic memories, magnetic drivers, magnetic sensitive elements, giant magnetoresistance devices, solid refrigeration, artificial intelligence, robots and the like. The phase transition temperature, magnetic property, magnetoresistance, magnetic strain and the like of the alloy can be adjusted by changing the vacancy amount of Mn and the substitution amount of Bi element in the alloy, namely changing the values of y and x.

3) The Bi substituted Mn lacking Mn provided by the invention₂The Sb-based alloy is a first-order magnetoelastic phase change obtained by firstly adjusting the vacancy of the transition element and then regulating the proportion of the main group element, and the preparation method is simple and convenient, has low energy consumption and low preparation cost, and is suitable for industrial production.

4) The invention provides Mn needing protection_2-ySb_1-xBi_xThe alloy realizes good first-order magnetoelastic phase change, and has abundant magnetic functional properties. Firstly, as the magnetic field increases, the phase transition temperature moves to a low temperature, and the high-temperature strong magnetic phase is trapped, and when the magnetic field reaches 8T, the phase transition shows almost complete dynamic trapping. Under the change of 0-5T magnetic field, obtainingUp to 3.9Jkg^-1k^-1The magnetic entropy change and the refrigeration temperature range of 35K, and simultaneously, the maximum magnetoresistance value of the series of alloys up to 67 percent under the same condition is obtained.

In addition, the invention provides Bi-doped Mn-deficient Mn₂The Sb-based alloy can generate a first-level magnetoelastic phase change from ferrimagnetism to paramagnetism driven by temperature, a magnetic field and stress, and the magnetization intensity, the resistance and the strain near the phase change generate great mutation, so that the series of alloys have great magnetocaloric effect, magnetoresistance effect and magnetostriction effect, and therefore the series of alloys can also be applied to the fields of solid refrigeration, giant magnetoresistance devices, artificial intelligence, robots and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a thermomagnetic curve of increasing and decreasing temperature under an external magnetic field of 0.01T in example 1 of the present invention;

FIG. 2 is a temperature-rise and temperature-fall thermomagnetic curve of example 3 of the present invention under an external magnetic field of 0.01T;

FIG. 3 is a temperature rise and decrease thermomagnetic curve of example 4 of the present invention under an external magnetic field of 0.01T;

FIG. 4 is a temperature-rise and temperature-fall thermomagnetic curve of example 5 under an external magnetic field of 0.01T;

FIG. 5 is the isothermal magnetization curves at different temperatures for example 6 of the present invention;

FIG. 6 is a temperature-increasing/decreasing thermomagnetic curve of example 7 under an external magnetic field of 0.01T;

FIG. 7 is a temperature-increasing/decreasing thermomagnetic curve of example 8 under an external magnetic field of 0.01T;

FIG. 8 is the thermomagnetic M (T) curve of the Mn deficiency of 0.22 followed by Bi substitution of 0, 0.03, 0.07 components under an external magnetic field of 0.01T in accordance with the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood and enable those skilled in the art to practice the present invention, the following embodiments are further described, but the present invention is not limited to the following embodiments.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. Unless otherwise specifically stated, the various starting materials, reagents, instruments and equipment used in the following examples of the present invention are either commercially available or prepared by conventional methods.

According to the invention, the proportion of main group elements is adjusted, alloy components are designed, and the element proportion in the alloy is adjusted to adjust adjacent magnetic moments which are arranged in parallel in the alloy to be arranged in an antiparallel manner, so that the first-order magnetoelastic phase change of the transition from ferrimagnetism to antiferromagnetic magnetism is realized, and finally, excellent functional properties such as wide-temperature-zone large magnetothermal effect, giant magnetoresistance, magnetostrain, thermal expansion and the like are obtained.

In the present invention, the samples obtained in examples 1 to 8 were all measured by the PPMS comprehensive physical property measurement system of QD corporation, and thermomagnetic curves at low magnetic fields were obtained.

Based on the above principle, actually the alloy expression:

the chemical general formula of the alloy is Mn_2-ySb_1-xBi_x(1) And 0 is<y<1 is the vacancy of Mn atom, 0<x.ltoreq.0.4 represents the substitution amount of Bi for Sb as a large-radius element in the same main group as Sb, and the general formula can be extended to Mn_1.97Sb_0.97Bi_0.03，Mn_1.93Sb_0.93Bi_0.07And the like.

The following specifically exemplifies the technical scheme of the present invention with reference to specific examples: