Magnetic properties and enhanced magnetocaloric effect in EuAl$_3$Si single crystals

TL;DR

This paper reports the growth and analysis of EuAl$_3$Si single crystals, revealing a strong magnetocaloric effect near 15 K, making it promising for magnetic refrigeration, with significant improvements over EuAl$_4$.

Contribution

It introduces EuAl$_3$Si single crystals with enhanced magnetocaloric properties and discusses the mechanism behind this improvement.

Findings

EuAl$_3$Si exhibits a ferromagnetic transition at 15 K.

Maximum magnetic entropy change of 13.4 J/kg K with 2 T field.

Refrigerant capacity of 166 J/kg and temperature change of 7.2 K.

Abstract

This study presents systematic investigations into the growth and physical properties of EuAl$_3$Si single crystals, encompassing magnetic, transport, and thermodynamic analyses. EuAl$_3$Si undergoes a ferromagnetic transition at $T_C$ = 15 K. A significant reversible magnetocaloric effect was observed around $T_C$. Strikingly, with a small change of magnetic field 2 T, the maximum values of magnetic entropy change (13.4 J/kg K), refrigerant capacity (166 J/kg) and adiabatic temperature change (7.2 K) are found. These parameters respectively are 60%, 148% and 64% larger than those of the parent compound EuAl$_4$, and suggest EuAl$_3$Si as an excellent candidate for magnetic refrigeration applications near the temperature of liquid hydrogen. The possible mechanism for this enhancement is also discussed.