Author/Authors :
Ozawa، Tadashi C. نويسنده , , Pantoja، Rigo نويسنده , , III، Enos A. Axtell, نويسنده , , Kauzlarich، Susan M. نويسنده , , Greedan، John E. نويسنده , , Bieringer، Mario نويسنده , , Jr.، James W. Richardson, نويسنده ,
Abstract :
The structure of Na2Ti2Sb2O has been investigated by temperature-dependent powder neutron diffraction. Na2Ti2Sb2O crystallizes in I4/mmm symmetry. The structure of this phase can be viewed as an anti-K2NiF4 type where Ti3+ ion is located between two oxygen atoms forming a square-planar lattice. Powder neutron diffraction studies of Na2Ti2Sb2O indicate that this compound has a structural distortion in the [Ti2Sb2O]2- layer at T~120 K. This transition corresponds well to the previously reported anomalous transition temperature of the magnetic susceptibility and electronic resistivity. Several models to explain the data are presented and discussed.
