On the inverse and conventional magnetocaloric effects in MnRhAs single crystals

TL;DR

This study investigates the complex magnetic and magnetocaloric properties of MnRhAs single crystals, revealing significant inverse and conventional effects, with potential applications in magnetic refrigeration across specific temperature ranges.

Contribution

It provides detailed analysis of the magnetic phase transitions and magnetocaloric effects in MnRhAs, highlighting the high negative magnetocaloric effect and the impact of different magnetic transitions.

Findings

High negative magnetocaloric effect at AFI-F transition.

Magnetic entropy change of about 3 J/kg K under 1 T.

Refrigerant capacity of approximately 900 J/kg.

Abstract

We report on the magnetic and magnetocaloric properties of a MnRhAs single crystal. The ternary arsenide exhibits a rather complex magnetic behaviour. A first order metamagnetic type transition from antiferromagnetic (AFI) to ferromagnetic (F) states takes place at Tt ~ 158 K, and a second order transition from ferromagnetic (F) to antiferromagnetic (AFII) states occurs at TC ~196 K, the paramagnetic state occurring at T > TN = 238 K. Magnetic entropy changes were calculated using, Maxwell relation and Clausius-Clapeyron equation. Both approaches are compared and discussed. The AFI-F transition in MnRhAs gives rise to an interestingly high level of negative magnetocaloric effect. Under a field change 0-1 T, the maximum magnetic entropy variation is about 3 J/kg K. For sufficiently high enough magnetic fields, the magnetocaloric working temperature range below 158 K can be covered. The F-AFII transition is accompanied by a relatively modest MCE (-2.3 J/kg K for 5 T at TC = 196 K), but it improves the working temperature span as well as the magnetocaloric properties. A minimum estimated refrigerant capacity of about 900 J/kg can be provided by a MnRhAs single crystal compound