Effects of Sr-doping on the giant magnetocaloric effect of EuTiO₃

The magnetic properties and magnetocaloric effect of Eu_1−xSr_xTiO₃ (x=0–0.1) compounds are investigated. With slight Sr-doping, the ferromagnetic (FM) coupling significantly increased and FM exchange is dominant in the delicate balance. A giant reversible magnetocaloric effect (MCE) and large refrigerant capacity (RC) for Eu_1−xSr_xTiO₃ compounds were observed. The values of −ΔS_M^max are evaluated to be around 10 J/kg K under a magnetic field change of 1 T and 21 J/kg K under a magnetic field change of 2 T, respectively. But, the values of RC are increased with the more Eu in EuTiO₃ to be substituted by Sr. Therefore, the giant reversible MCE and large RC make the Eu_1−xSr_xTiO₃ compound a good candidate for magnetic refrigerant working at low-temperature and low-field.