Compounds with large magnetic entropy changes and their preparation

A compound, magnetic entropy change technology, applied in magnetic objects, magnetic materials, electrical components and other directions, can solve the problems of restricting magnetic refrigeration, insoluble, insufficient magnetic entropy change, etc., achieving simple manufacturing process, adjustable Curie temperature, The effect of increasing magnetic entropy
CN1584082AInactive Publication Date: 2005-02-23UNIV OF SCI & TECH BEIJING
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
UNIV OF SCI & TECH BEIJING
Publication Date
2005-02-23
Estimated Expiration
Not applicable · inactive patent

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Abstract

A big magnetic entropy variation compound and its preparing method are disclosed. It consists of NixMnyGaz (50 is less than or equal to x is less than or equal to 56, 22 is less than or equal to y is less than or equal to 30, 22 is less than or equal to z is less than or equal to 30), with martensite and magnetic conversion under -80deg.C- 80deg.C. When 53 is less than or equal to x is less than or equal to 56, 19 is less than or equal to y is less than or equal to 22, 23 is less than or equal to z is less than or equal to 26, it make austenite phase-transition temperature range and magnetic transition temperature between -20deg.C-80 deg.C by component regulation. It is prepared by proportioning nickel, mangan and gallium etc. raw materials by chemical component, laying vacuum arc furnace or inducing furnace, vacuum pumping up to 10 to the power -1 , passing argon, smelting and cooling to obtain uniform compound, homogeneous treating the compound for 24-120 hrs under 900-1100deg.C, and annealing for 12-72 hrs under 600-800deg.C. Its advantages include simple process, big magnetic entropy and regulating temperature.
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Description

technical field

[0001] The invention belongs to the technical field of magnetic refrigeration materials, and in particular provides a compound with large magnetic entropy change and a preparation method thereof. Background technique

[0002] Magnetic refrigeration is realized by using a magnetic field to change the order degree of the spin orientation spatial distribution of the atoms of the refrigeration working substance, causing a change in magnetic entropy. When the refrigerant is demagnetized adiabatically, the temperature decreases; when the refrigerant is magnetized adiabatically, the temperature increases. It can also be said that when the refrigerated substance is isothermally demagnetized, it absorbs heat; when it is isothermally magnetized, it releases heat. This is the magnetocaloric effect, also known as the magnetic calorie effect, referred to as the magnetic card effect

[0003] Magnetic entropy is a characterization of the degree of magnetic order. As long a...

Claims

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