Giant reversible magnetocaloric effect in ErMn ₂Si ₂ compound with a second order magnetic phase transition

The magnetic properties and magnetocaloric effect (MCE) in the ternary intermetallic compound ErMn ₂Si ₂ have been studied by magnetization and heat capacity measurements. A giant reversible MCE has been observed, accompanied by a second order magnetic phase transition from paramagnetic to ferromagnetic at ∼4.5 K. Under a field change of 5 T, the maximum value of magnetic entropy change (-δS _M ^max) is 25.2 J kg ^-1 K ^-1 with no thermal and field hysteresis loss, and the corresponding maximum value of adiabatic temperature change (δT _ad ^max) is 12.9 K. Particularly, the values of -δS _M ^max and δT _ad ^max reached 20.0 J kg ^-1 K ^-1 and 5.4 K for a low field change of 2 T, respectively. The present results indicate that the ErMn ₂Si ₂ compound is an attractive candidate for low temperature magnetic refrigeration.