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

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.