Influences of La and Ce doping on giant magnetocaloric effect of EuTiO

Giant reversible magnetocaloric effects and magnetic properties in Eu_0.9R_0.1TiO₃ (R=La, Ce) are investigated. The antiferromagnetic ordering of pure EuTiO₃ can significantly change to be ferromagnetic as substitution of La (x=0.1) and Ce (x=0.1) ions for Eu²⁺ ions. The values of -ΔS_M and RC are evaluated to be 10.8 J/(kg·K) and 51.8 J/kg for Eu_0.9Ce_0.1TiO₃ and 11 J/(kg·K) and 39.3 J/kg for Eu_0.9La_0.1TiO₃ at a magnetic field change of 10 kOe, respectively. The large low-field enhancements of -ΔS_M and RC can be attributed to magnetic phase transition. The giant reversible MCE and large RC suggest that Eu_0.9R_0.1TiO₃ (R=La, Ce) compounds could be promising materials in low temperature and low magnetic field refrigerants.