Large Magnetocaloric effect and magnetic phase transitions in Nd$_2$NiMnO$_6$

TL;DR

This study investigates Nd$_2$NiMnO$_6$'s magnetic and magnetocaloric properties, revealing a high relative cooling power and broad entropy change profile, making it a promising material for magnetic refrigeration.

Contribution

The paper combines experimental and theoretical methods to demonstrate Nd$_2$NiMnO$_6$'s superior magnetocaloric performance and elucidates the mechanism behind its enhanced RCP.

Findings

RCP of approximately 300 J/Kg near T_C

Broad magnetic entropy change profile

Nd$_2$NiMnO$_6$ outperforms nonmagnetic counterparts

Abstract

We present combined experimental and theoretical investigations on the magnetic and magnetocaloric behavior of Nd$_2$NiMnO$_6$. The relative cooling power (RCP) which quantifies the usefulness of a magnetocaloric (MC) material is estimated to be $\approx 300$ J/Kg near the ferromagnetic transition at $T_C \approx 195$ K. This RCP is comparable to the best known MC materials. Additionally, the magnetic entropy change has a broad profile ($T_C - 50~{\rm K} < T < T_C + 50~{\rm K}$) leading to an enhancement in the working-range of temperatures for magnetocaloric based cooling. These features make Nd$_2$NiMnO$_6$ a superior magnetocaloric material compared for example, to the nonmagnetic counterpart Y$_2$NiMnO$_6$. We identify the mechanism for the enhanced RCP which can guide search for future MC materials.