Crystal Structure of the Hexagonal Modification of Lutetium-Stabilized Gadolinium Titanate Gd1.8Lu0.2TiO5

The crystal structure of the high-temperature hexagonal modification of a rare-earth titanate, namely, Gd1.8Lu0.2TiO5, is determined using the single-crystal X-ray diffraction technique [a = 3.663(3) Å,c = 11.98(1) Å, space group P6^sub 3^/mmc, Z = 1.2, 139 F(h, k, l),R = 0.057]. The structure is characterized by the closest six-layer packing of oxygen atoms [ABABAB] in which octahedral holes are occupied by gadolinium atoms and the second cation position is located at a face shared by two adjacent tetrahedral holes. This trigonal bipyramid is also occupied by titanium and lutetium atoms, as well as by the gadolinium atoms not involved in the octahedral position.[PUBLICATION ABSTRACT]