Enhanced magnetocaloric effect from Zn substitution in perovskite Eu(Ti,Zn)O3 compounds

The magnetic transition from antiferromagnetism to ferromagnetism (AFM-FM) in EuTiO3 provides the feasibility of regulating its magnetic properties. Foreign element substitution has been proved to be an effective way to achieve AFM-FM switching and enhanced magnetocaloric effect (MCE) in EuTiO3 system. In this study, a series of Zn substituted Eu(Ti,Zn)O3 perovskites were synthesized, the crystal structure, magnetic properties, and MCE were investigated. All the compounds crystallize in a pure cubic perovskite phase with the space group Pm3m, and undergo a second-order phase transition at the ordering temperature 6.0 K. The substitution of Zn can significantly regulate the magnetic properties and enhance the ferromagnetic coupling, thus leading to an enhanced MCE in the Eu(Ti,Zn)O3 compounds. Under field change of 0–1, 0–2, and 0–5 T, the −ΔSMmax values are 10.3, 21.4, and 38.5 J·kg−1·K−1 for EuTi0.9375Zn0.0625O3, 10.8, 22.7, and 41.1 J·kg−1·K−1 for EuTi0.875Zn0.125O3, 12.5, 25.3, and 45.0 J·kg−1·K−1 for EuTi0.8125Zn0.1875O3, respectively. Besides, the compounds exhibit prominent refrigeration capability and temperature averaged entropy change. The considerable magnetocaloric performances make the Eu(Ti,Zn)O3 perovskites potential candidate materials for cryogenic magnetic refrigeration.