Effects of pressure on the magnetostructural and magnetocaloric properties of isostructurally alloyed (MnNiSi)1-x(FeCoGe)x

TL;DR

This study explores how hydrostatic pressure influences the magnetostructural and magnetocaloric properties of an alloy system, revealing pressure-induced shifts in phase transition temperatures while maintaining large entropy changes, enhancing cooling efficiency.

Contribution

It introduces a new alloy system, (MnNiSi)1-x(FeCoGe)x, demonstrating pressure-sensitive magnetocaloric effects with potential for improved cooling applications.

Findings

Pressure shifts phase transition to lower temperatures (-41 K at 3.43 kbar)

Large isothermal entropy change maintained under pressure (-143.7 J/kg K at 5 T)

Pressure combined with magnetic field enhances cooling power

Abstract

The isostructural alloying of two compounds with extremely different magnetic and thermo-structural properties has resulted in a new system, (MnNiSi)1-x(FeCoGe)x, that exhibits extraordinary magnetocaloric properties with an acute sensitivity to applied hydrostatic pressure (P). Application of hydrostatic pressure shifts the first-order phase transition to lower temperature ($\Delta$ T=-41 K with P=3.43 kbar) but preserves the giant value of isothermal entropy change (-$\Delta$S$\max$=143.7 J/kg K for a field change of {\Delta}B=5 T at atmospheric pressure). Together with the magnetic field, this pressure-induced temperature shift can be used to significantly increase the effective relative cooling power.