Anisotropic magnetic properties and giant rotating magnetocaloric effect in double-perovskite Tb2CoMnO6

TL;DR

This study reveals the highly anisotropic magnetic and magnetocaloric properties of Tb2CoMnO6, demonstrating a giant rotational magnetocaloric effect driven by magnetic anisotropy and complex magnetic ordering.

Contribution

It provides the first detailed analysis of anisotropic magnetocaloric effects in double perovskite Tb2CoMnO6, highlighting its potential for magnetic cooling applications.

Findings

Giant rotational magnetocaloric effect of 20.8 J/kg K.

Distinct magnetic anisotropy with ferromagnetic order along c-axis.

Temperature-dependent metamagnetism affecting entropy change.

Abstract

We investigated the anisotropy of the magnetic and magnetocaloric properties of singlecrystalline double perovskite Tb2CoMnO6, which crystallizes in a monoclinic P21/n structure. Due to dissimilar magnetic anisotropy, the ferromagnetic order of the Co2+ and Mn4+ moments emerges along the c-axis at TC = 100 K, and the larger Tb3+ moments align perpendicular to the c-axis, below TTb = 15 K. The intricate temperature development of the metamagnetism along the c-axis results in a large negative change in the magnetic entropy at low temperature. On the other hand, the larger but almost reversible magnetization, perpendicular to the c-axis, results in a small and positive entropy change. This highly anisotropic magnetocaloric effect (MCE) leads to a giant rotational MCE, estimated to be 20.8 J/kg K. Our findings, based on the magnetic anisotropy in Tb2CoMnO6, enrich fundamental and applied research on magnetic materials, considering the distinct magnetic characteristics of double perovskites.