Observation of giant magnetocaloric effect under low magnetic field in Eu1−xBaxTiO3

The magnetic properties and magnetocaloric effect in Eu1−xBaxTiO3 (x = 0, 0.04, 0.08, 0.1) compounds are investigated. With slight Ba-doping, the antiferromagnetic ordering of pure EuTiO3 can be significantly changed to ferromagnetic due to the size Ba2+ ion bigger than Eu2+. A giant reversible magnetocaloric effect and large RC in Eu1−xBaxTiO3 compounds were observed. The maximum value of magnetic entropy change (−ΔSMmax) reaches to 41.4 J/kg K for Eu0.92Ba0.08TiO3 under the magnetic field change of 5 T. Especially, under the magnetic field changes of 1 and 2 T, the values of −ΔSMmax are evaluated to be 12.5 and 23.4 J/kg K and the maximum values of RC are 54 and 119 J/kg, without magnetic and thermal hysteresis for Eu0.92Ba0.08TiO3. Therefore, the giant reversible magnetocaloric effect and large RC make the Eu1−xBaxTiO3 compounds could be considered as a good candidate material for low-temperature and low-field magnetic refrigerant.