Structures of two high-temperature Dy2TiO5 modifications

Single crystals of two structural modifications of high-temperature dysprosium titanate Dy₂TiO were grown. Using X-ray diffraction, the crystal structure of the cubic modification (space group Fd3m, a = 10.28(1)Å, Z = 10.4) was refined and the structure of a new monoclinic modification (space group B2/m, a = 10.33(1)Å, b = 3.653(5)Å, c = 7.306(6)Å, β = 90.00(7)°, Z = 2.4), which crystallizes in minor amounts together with the cubic phase, was determined. The lowering of symmetry from cubic to monoclinic is due to different distributions of the Dy³⁺ and Ti⁴⁺ cations over the sites present in the cubic cell.