A kind of rare earth palladium magnesium low temperature magnetic refrigeration material and its preparation method

A low-temperature magnetic refrigeration and rare earth technology, applied in the direction of heat exchange materials, chemical instruments and methods, etc., can solve the problems of small magnetic entropy and commercial application limitations, and achieve significant magnetic entropy change, high magnetic refrigeration capacity, and easy implementation Effect
CN105671395BActive Publication Date: 2017-05-31NORTHEASTERN UNIV LIAONING
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
NORTHEASTERN UNIV LIAONING
Publication Date
2017-05-31

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Abstract

A rare earth palladium magnesium low-temperature magnetic refrigeration material and its preparation method. The general chemical formula of the material is: RE4-Pd-Mg, RE is one or two of Ho, Er or Tm, according to the atomic ratio RE: Pd: Mg =4:1:1; Preparation method: 1) Mixing; 2) Inert gas closed environment; 3) Sintering: Keep the quartz container at 850-920°C for 10-20 minutes, then lower the temperature to 650-720°C and keep it warm 3 to 5 hours, natural cooling; 4) Tablet molding; 5) Sealed annealing: Place the formed material into a quartz tube and seal, anneal at 660 to 700°C for 36 to 48 hours, and naturally cool to obtain the finished product. The material of the invention has significant magnetic entropy change and high magnetic refrigeration capacity. The magnetic transition temperature and the maximum magnetic entropy change can be continuously adjusted with changes in composition within the temperature range of 5 to 40K; it has good magnetic and thermal reversible properties. The method of the present invention adopts slow heating and step-by-step reaction to overcome Mg volatilization; the process is simple and easy to implement.
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Description

technical field

[0001] The invention belongs to the technical field of magnetic functional materials, in particular to a rare earth palladium magnesium RE 4 PdMg low temperature magnetic refrigeration material and preparation method. Background technique

[0002] Magnetic refrigeration material is a new type of magnetic functional material. It is a non-polluting refrigerant material that uses the magnetic entropy effect (magnetocaloric effect, also known as the magnetic card effect) of magnetic materials to achieve refrigeration. The magnetic entropy effect is one of the intrinsic properties of magnetic materials, and its size depends on the intrinsic physical properties of magnetic materials. Magnetic refrigeration is the use of an external magnetic field to make the magnetic moment of the magnetic working medium change in an orderly and disorderly manner (phase transition), causing the magnet to absorb heat and release heat to perform a refrigeration cycle. The refrigera...

Claims

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