YCrWO6: Polar and Magnetic Oxide with CaTa2O6‑Related Structure

A new polar and magnetic oxide, YCrWO6, was successfully synthesized and characterized. YCrWO6 crystallizes in polar orthorhombic space group Pna21 (no. 33) of edge-sharing dimers of CrO6 and WO6 octahedra, which are connected by corner-sharing to form a three-dimensional framework structure with Y3+ cations located in the channels. The structure of YCrWO6 is related to that of CaTa2O6; however, the ordering of Cr3+ and W6+ in the octahedral sites breaks the inversion symmetry of the parent CaTa2O6 structure. X-ray absorption near edge spectroscopy of YCrWO6 confirmed the oxidation state of Cr3+ and W6+. Temperature-dependent optical second harmonic generation measurements on YCrWO6 confirmed the noncentrosymmetric character and evidenced a noncentrosymmetric-to-centrosymmetric phase transition above 800 °C. Piezoresponse force microscopy measurements on YCrWO6 at room temperature show strong piezoelectric domains. Magnetic measurements of YCrWO6 indicate antiferromagnetic order at TN of ∼22 K with Weiss temperature of −34.66 K.