Magnetism, magnetocaloric and magnetodielectric properties of DyVWO6: a new aeschynite-type polar antiferromagnet

Abstract

We report magnetic, magnetocaloric and magnetodielectric properties of a new polar magnet DyVWO6 crystallizing in the orthorhombic structure (Pna21). It consists of edge-shared dimers of VO6 and WO6 octahedra, which are connected by corner-sharing to a form three-dimensional network structure with Dy3+ cations located in the channels. The ordering of V3+ and W6+ ions in the octahedral sites breaks the inversion symmetry of the parent-CaTa2O6 structure (Pnma). Magnetic and heat capacity measurements show that the V3+ and Dy3+ ions undergo antiferromagnetic transitions at ${T}_{N}^{V}$ ~ 5 K and ${T}_{N}^{Dy}$ ~ 2.5 K, respectively. Isothermal magnetization shows a metamagnetic transition at the applied magnetic field of 1 T at 2 K that corresponds to a transition from the antiferromagnetic (AFM) to ferromagnetic (FM) spin structure. Further, this compound exhibits significant magnetocaloric effect (MCE) with a maximum magnetic entropy change (−∆${S}_{M}^{\max }$) of 8.45 J Kg−1 K−1 at 7 T. In addition to this, we observe a drop in dielectric constant below ${T}_{N}^{V}$ with a low temperature dielectric relaxation.