Extremely low temperature magnetic refrigeration material and preparation method and application thereof

Abstract

The invention discloses an extremely-low-temperature magnetic refrigeration material and a preparation method and application thereof, and belongs to the technical field of magnetic refrigeration. The chemical general formula of the extremely low temperature magnetic refrigeration material is LiREF4, and RE is any one of rare earth elements Tb, Dy, Ho and Er. The phase change temperature of the extremely-low-temperature magnetic refrigeration material is smaller than or equal to 3.5 K, and the extremely-low-temperature magnetic refrigeration material has the quite remarkable low-magnetic-field large magnetothermal effect, under the magnetic field changes of 0-0.5 T, 0-1 T and 0-2 T, the maximum magnetic entropy changes of the material reach up to 21.4 J kg-1. K <-1 >, 33.1 J kg-1. K <-1 > and 49.0 J kg-1. K <-1 > respectively, and the design and manufacturing cost of equipment can be greatly reduced. Moreover, the preparation method of the extremely-low-temperature magnetic refrigeration material is simple, short in period, low in energy consumption, green, energy-saving, safe, remarkable in environmental protection advantage and suitable for large-scale preparation.

Description

technical field [0001] The invention belongs to the technical field of magnetic refrigeration, and in particular relates to an extremely low temperature magnetic refrigeration material and a preparation method and application thereof. Background technique [0002] Since the 20th century, refrigeration technology has achieved unprecedented development and has been widely used in various fields such as human life, modern industry, scientific research, biomedicine, and aerospace and military industries. Among them, low-temperature refrigeration, especially extremely low-temperature refrigeration, is not only an important condition for the development of high-precision technologies such as low-temperature electronics and low-temperature physics, but also a key supporting technology in the field of aerospace and military industry, which is of great significance to space strategy and national defense security. In recent years, some major scientific progress, especially in the fiel...

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Problems solved by technology

CN 104531085 A discloses a kind of Gd(OH) 3 Single crystal, the maximum magnetic entropy change is as high as 42.1J kg at 2K under the magnetic field changes of 0-3T and 0-7T -1 ·K -1 and 62.0J kg -1 ·K -1 , has a good application prospect in the field of extremely low temperature magnetic refrigeration, but its maximum magnetic entropy change under the magnetic field changes of 0-0.5T and 0-1T is only 2.1J kg -1 ·K -1 and 9.0J kg -1 ·K -1 ; At the same time, the preparation cycle of this material is long, and it needs about 5 days to crystallize at 250°C, and the volume of the reaction kettle used is only 23mL, so it is difficult to achieve mass production

CN 107043394 B discloses an inorganic-organic hybrid gadolinium-based molecular-based low-temperature magnetic refrigeration material. At 2K, its maximum magnetic entropy changes under 0-1T, 0-2T and 0-7T magnetic field changes are respectively 13.8J kg -1 ·K -1 , 27.0J·kg -1 ·K -1 and 46.6J kg -1 ·K -1 , but the maximum magnetic entropy change under the 0-0.5T magnetic field change is only 5.2J kg -1 ·K -1 ; and the preparation process of this material requires crystallization at 80°C for 3 days, and the preparation cycle is long; the volume of the reaction kettle used in this process is only 10mL, which is not suitable for mass production, and its commercial application is limited

In 2006, Numazawa et al reported a polycrystalline GdLiF 4 material, the phase transition temperature of the material is below 0.5K, and its maximum magnetic entropy change is 44.9J kg under the magnetic field changes of 0-2T and 0-5T respectively -1 ·K -1 and 64.8J kg -1 ·K -1 , but did not provide the magnetic entropy change value of the material under the change of 0-0.5T and 0-1T low magnetic field

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