Gd-Mn-based amorphous magnetic refrigeration material and preparation method thereof

Abstract

The invention relates to the field of magnetic materials and discloses a Gd-Mn-based amorphous magnetic refrigeration material and a preparation method thereof. The Gd-Mn-based amorphous magnetic refrigeration material has a chemical general formula of Gd65Mn35-xMx (x is greater than 0 and less than or equal to 10), wherein M represents Si or Ge. The preparation method comprises the following steps of 1, weighing pure elements according to a mass percentage of the elements shown in the chemical general formula and mixing, 2, repeatedly smelting the mixed elements to obtain a uniform alloy ingot, and 3, crushing the uniform alloy ingot into small blocks, and carrying out melt-spinning to obtain a stripe having the width of 1-2 millimeters and thickness of 30-50 micrometers, wherein the stripe is the Gd-Mn-based amorphous magnetic refrigeration material. The preparation method has simple processes, avoids long-term heat treatment, has a low cost and is suitable for industrial production. The Gd-Mn-based amorphous magnetic refrigeration material obtained by the preparation method can produce ferromagnetic-paramagnetic two-stage magnetic phase transition in magnetization, has a large refrigeration capacity and is suitable as a magnetic refrigeration material.

Description

technical field [0001] The invention relates to an amorphous magnetic material, in particular to a Gd-Mn based amorphous magnetic refrigeration material and a preparation method thereof. Background technique [0002] With the enhancement of people's awareness of environmental protection and the aggravation of the global energy crisis, the traditional gas compression refrigeration technology is subject to more and more controversies and challenges. Even in the case of continuous technological innovation, its refrigeration efficiency is still only 5-10% of the reverse cycle of the Carnot heat engine, and the energy consumption is very serious. At the same time, the traditional gas refrigeration technology uses chemical liquid refrigerants (such as freon), which are easy to release chemicals that destroy the ozone layer during the operation of the refrigerator, leading to the intensification of the global warming effect. At present, emerging refrigeration technologies mainly i...

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Problems solved by technology

Gd discovered in 1997 by American Ames Laboratory 5 Si 2 Ge 2 (5:4 system), La(Fe,Si) discovered by Hu Fengxia, Institute of Physics, Chinese Academy of Sciences in 2001 13 (1:13 system), the Mn-Fe-P-As compound reported by Tegus in 2002, and the later Heusler alloy Ni-Mn-X (X=Ga, Sn, In, Sb) all occur in the first order near the magnetic transition temperature The giant magnetocaloric effect is obtained by phase change, but the magnetic entropy change of this type of magnetic refrigeration material changes suddenly near the transition temperature, and the transition temperature range is narrow, which is difficult to satisfy the requirements of the Ericsson magnetic refrigeration cycle to keep the magnetic entropy change basically constant in a wide temperature range. requirements; while the magnetic entropy change of the secondary phase change magnetic refrigeration material has a large temperature span near its magnetic transition temperature, the magnetic entropy change is relatively gentle, and the cooling capacity is large.

Pure Gd is a typical secondary phase change material, but Gd has active chemical properties, is easy to oxidize, has poor corrosion resistance, low mechanical strength, and is expensive. There are still some problems in commercialization.

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