Giant rotating magnetocaloric effect induced by highly texturing in polycrystalline DyNiSi compound.

Hu Zhang,Jinling Jin,Yawei Li,Yajiao Ke,Yi Long,Enke Liu,Baogen Shen

doi:10.1038/srep11929

Abstract

Large rotating magnetocaloric effect (MCE) has been observed in some single crystals due to strong magnetocrystalline anisotropy. By utilizing the rotating MCE, a new type of rotary magnetic refrigerator can be constructed, which could be more simplified and efficient than the conventional one. However, compared with polycrystalline materials, the high cost and complexity of preparation for single crystals hinder the development of this novel magnetic refrigeration technology. For the first time, here we observe giant rotating MCE in textured DyNiSi polycrystalline material, which is larger than those of most rotating magnetic refrigerants reported so far. This result suggests that DyNiSi compound could be attractive candidate of magnetic refrigerants for novel rotary magnetic refrigerator. By considering the influence of demagnetization effect on MCE, the origin of large rotating MCE in textured DyNiSi is attributed to the coexistence of strong magnetocrystalline anisotropy and highly preferred orientation. Our study on textured DyNiSi not only provides a new magnetic refrigerant with large rotating MCE for low temperature magnetic refrigeration, but also opens a new way to exploit magnetic refrigeration materials with large rotating MCE, which will be highly beneficial to the development of rotating magnetic refrigeration technology.

Highlights

Large rotating magnetocaloric effect (MCE) has been observed in some single crystals due to strong magnetocrystalline anisotropy
Magnetocaloric effect (MCE) is a magneto-thermodynamic phenomenon in which a temperature change in magnetic material is caused by the variation of external magnetic field[1,2]
In order to improve the applications of magnetic refrigeration technology, it is very important to search for materials with large MCE

Summary

Introduction

Large rotating magnetocaloric effect (MCE) has been observed in some single crystals due to strong magnetocrystalline anisotropy. Here we observe giant rotating MCE in textured DyNiSi polycrystalline material, which is larger than those of most rotating magnetic refrigerants reported so far. This result suggests that DyNiSi compound could be attractive candidate of magnetic refrigerants for novel rotary magnetic refrigerator. A novel rotary magnetic refrigerator, in which a large MCE can be obtained by rotating the magnetic refrigerant in a constant field instead moving it in and out of magnet, was proposed based on the concept of rotating MCE12,14 This rotary magnetic refrigerator has certain advantages in comparison with conventional counterpart, such as simple and compact device, and high efficiency. It is highly significant to exploit polycrystalline materials with large rotating MCE especially under low field change (i.e., < 20 kOe) from both fundamental and practical points of view

Methods

Results

Conclusion