Mo doped mn-fe-p-si based magnetic refrigeration material and preparation method thereof

Abstract

The invention discloses a Mo-doped MnFePSi-based alloy magnetic refrigeration material and a preparation method thereof, belonging to the technical field of magnetic refrigeration materials. The material composition is Mn 1.1 Fe 0.9‑X Mo X P 0.43 Si 0.57 , 0.02≤X≤0.04, the preparation steps are: under the protection of argon atmosphere, ball mill manganese sheet, iron powder, molybdenum powder, phosphorus block and silicon block according to the molar ratio of each element in the chemical formula; the powder after ball milling Pressed into a sample; the sample was sealed in a quartz tube filled with argon protection, and quenched in cold water after annealing. In the invention, by doping an appropriate amount of Mo into the MnFePSi material, the phase transition temperature can be continuously adjusted around room temperature, greatly reducing thermal hysteresis, while maintaining a large magnetic entropy change, which is beneficial to the application of the material in the field of room temperature magnetic refrigeration.

Description

technical field [0001] The invention relates to the field of room temperature magnetic refrigeration, in particular to a Mo-doped MnFePSi-based alloy magnetic refrigeration material and a preparation method thereof. Background technique [0002] Magnetic refrigeration technology is a brand-new refrigeration technology that uses magnetic materials as working fluids to realize refrigeration by using the change of magnetic entropy of materials during the process of adding a magnetic field and removing the magnetic field. Compared with traditional gas compression refrigeration, magnetic refrigeration technology has no pollution, low noise, small footprint, and high energy conversion efficiency. It is considered to be a new green refrigeration technology that is expected to solve human energy problems and environmental pollution problems. The key to the application of magnetic refrigeration technology lies in the selection and development of suitable magnetic refrigerants. The r...

AI Technical Summary

Problems solved by technology

However, since the MnFePSi material undergoes a first-order magnetoelastic phase transition, the phase transition process is accompanied by large thermal hysteresis, and the mechanical stability is poor and brittle, which is not conducive to the practical application of the material.

Previous studies have found that the Curie temperature Tc and thermal hysteresis of the material can be adjusted by changing the Mn / Fe ratio and P / Si ratio, but this will weaken the mixed magnetic properties of the material and have an adverse effect on the magnetocaloric effect; it has also been found that boron-doped Atoms can significantly increase the Curie temperature Tc of the material, and at the same time significantly reduce the thermal hysteresis, but this adjustment only increases Tc in one direction and is not easy to control

Images