Electronic, Magnetic and Magnetocaloric Properties of Hole-Doped La₂MnFeO₆ and their Potential for Magnetic Refrigeration

Magnetic refrigeration at room-temperature is a technology that could potentially be more environmentally-friendly, efficient and affordable than traditional refrigeration. Known ferromagnets that satisfy the requirements of near room temperature Curie temperature and large refrigerant capacity are expensive. Double Perovskites La₂MnXO₆ with X=Ni,Co have refrigerant capacity comparable to the more expensive materials but their Curie temperature T_c is low [1]. Previous theoretical studies have reproduced the trend in T_c of these materials and shown that strong electronic interactions in Fe-d orbitals [2] make the X=Fe compound a ferrimagnet. Based on this insight, we use ab initio, mean-field and Monte-Carlo calculations to propose two materials with promising magnetocaloric properties. They are obtained by hole doping the X=Fe compounds by substituting half of the lanthanum with Sr or Ba, LaBaMnFeO₆ and LaSrMnFeO₆ [3].

[1] M. Balli et al, Journal of Applied Physics 115, 173904 (2014).
[2] C. Gauvin-Ndiaye et al, PRB 98, 125132 (2018).
[3] C. Gauvin-Ndiaye, A.-M.S. Tremblay, R. Nourafkan, arXiv:1809.07813