Preparation method of MnAsP compound with efficient room temperature magnetic refrigeration performance

Abstract

The invention discloses a preparation method of a MnAsP compound with efficient room temperature magnetic refrigeration performance. The preparation method is characterized in that: a room temperature magnetic refrigeration material with large grain size distribution and high comprehensive refrigeration performance can be quickly prepared by taking high-purity metal Mn and non-metal As, and P element as raw materials, taking argon as a protective gas, and adopting a mechanical alloying (ball milling) method. The preparation method of the MnAsP compound with efficient room temperature magneticrefrigeration performance can quickly prepare the MnAs compound with large grain size distribution and partially nano-crystallized grains in a large amount. Simultaneously, the preparation method obtains a magnetic refrigeration effect that the magnetic entropy change reaches 11.3J/kg.K in room temperature range under a 2T magnetic field. At the same time, the thermal lag can be reduced to 2K andcan reach requirements on actual room temperature magnetic refrigeration application.

Description

technical field [0001] The invention belongs to the field of new functional materials. Background technique [0002] Today's world has more and more extensive demand for refrigeration technology, while traditional (gas compression) refrigeration technology seriously pollutes the environment, destroys the ozone layer of the atmosphere, and causes the greenhouse effect. With the signing of the Montreal Agreement banning Freon in 1987, the research on magnetic refrigeration based on the magnetocaloric effect is becoming the forefront of refrigeration technology. High refrigeration efficiency (up to 30-60% of Carnot cycle, traditional gas compression refrigeration is only 20%), green environmental protection, low consumption and low noise make it present an attractive application prospect. The magnetocaloric effect that magnetic refrigeration technology relies on is the intrinsic property of magnetic materials, which means that the temperature of magnetic working fluid will inc...

AI Technical Summary

Problems solved by technology

Due to the volatility of As, the composition of MnAs alloys is difficult to control, and the preparation is very difficult. The traditional preparation method generally adopts multi-step sintering method, and it takes at least 15 days to prepare samples.

In addition, the thermal hysteresis in the MnAs alloy is as high as 10-30K, which is the biggest bottleneck for the industrialization of all first-order phase transition giant magnetic card materials.

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