Magnetic, magnetodielectric, and magnetocaloric properties of new polar oxides RCrWO6 (R = Sm, Eu, Gd, and Tb)

Abstract

We report new magnetic oxides RCrWO6 (R = Sm, Eu, Gd, and Tb) crystallizing in the polar orthorhombic structure (Space Group: Pna21), where edge-shared dimers of CrO6 and WO6 octahedra are connected by sharing corners and establish a three-dimensional framework. All these compounds exhibit antiferromagnetic ordering of Cr3+ spins at TN ∼ 28–32 K, except SmCrWO6, which shows weak ferromagnetism below TN = 32 K. Isothermal magnetization curves of RCrWO6 (R = Gd and Tb) at low temperatures show field-induced metamagnetic transition. Further, a dielectric anomaly at TN in all these compounds evidences the magnetodielectric effect. In addition, GdCrWO6 demonstrates magnetocaloric effect (MCE) with a maximum magnetic entropy change of 9.22 J kg−1K−1 at 70 kOe with relative cooling power (RCP) ∼ 101 J kg-1. On the other hand, TbCrWO6 exhibits both conventional and inverse magnetocaloric effects with significant entropy change and RCP.