Dzyaloshinskii-Moriya interaction in Nd$_{2}$Fe$_{14}$B as the origin of spin reorientation and rotating magnetocaloric effect

TL;DR

This study reveals that Dzyaloshinskii-Moriya interactions are the key factor behind spin reorientation in Nd₂Fe₁₄B and significantly influence its magnetocaloric properties, challenging previous assumptions about magnetic anisotropy dominance.

Contribution

First demonstration that Dzyaloshinskii-Moriya interactions cause spin reorientation in Nd₂Fe₁₄B, highlighting their importance in magnetic behavior and applications.

Findings

Dzyaloshinskii-Moriya interactions induce spin reorientation in Nd₂Fe₁₄B.

Spin reorientation leads to a notable rotating magnetocaloric effect.

Dzyaloshinskii-Moriya interactions significantly affect magnetic properties in Nd₂Fe₁₄B.

Abstract

The mechanism of spin reorientation in Nd$_{2}$Fe$_{14}$B, which is a host crystal of a well-known neodymium permanent magnet, is studied by combining first-principles calculations and Monte Carlo simulations. The spin reorientation is thought to be derived from crystal field effects and gets less attention because of the undesirable property for hard magnet application. Dzyaloshinskii-Moriya interactions are usually less attractive or often ignored in rare-earth bulk systems, including permanent magnets such as Nd$_{2}$Fe$_{14}$B since people believe that the magnetic anisotropy is more dominant than the Dzyaloshinskii-Moriya interactions. However, in this study, we have found, for the first time, that the spin reorientation in Nd$_{2}$Fe$_{14}$B is attributed to Dzyaloshinskii-Moriya interactions. We have found, furthermore, the spin reorientation in Nd$_{2}$Fe$_{14}$B yields a great stage of rotating magnetocaloric effect at practical application level. We have found that the Dzyaloshinskii-Moriya interactions definitely contributes to the physical properties as a non-negligible effect in magnetic materials.