Structural, magnetic properties and large cryogenic magnetocaloric effect (MCE) in RE2MgTiO6 (RE = Tb, Dy, Ho and Er) double perovskite (DP) oxides

We have systematically studied the crystal structure, cryogenic magnetic properties and MCE in RE2MgTiO6 (RE = Tb, Dy, Ho and Er) DP oxides. The four RE2MgTiO6 samples are all found to crystallize in a monoclinic DP structure (P21/n space group). The Néel temperature (TN) are found to be 4.7, 4.5, 3.1 and 2.1 K for RE2MgTiO6 (RE = Tb, Dy, Ho and Er) DP oxides, respectively. Moreover, the maximum magnetic entropy change (-ΔSMmax) together with relative cooling power (RCP) near TN under a magnetic field change (ΔH) of 0–7 T are evaluted to be 16.85, 360.59 for Tb2MgTiO6, 17.72, 381.05 for Dy2MgTiO6, 15.92, 398.14 for Ho2MgTiO6 and 22.95 J/kg K, 459.09 J/kg for Er2MgTiO6, respectively. The excellent cryogenic MCE suggest that RE2MgTiO6 (RE = Tb, Dy, Ho and Er) DP oxides can be used as a promising candidate material for cryogenic magnetic refrigeration.