STRUCTURE REFINEMENT OF THE SEMIMETALLIC OXIDE SRTL2O4 - A NEUTRON-DIFFRACTION STUDY

Strontium thallium oxide, SrTl2O4, M(r) = 559.4, orthorhombic, Pnam, a = 10.0451 (2), b = 11.6905 (2), c = 3.40860 (4) angstrom, V = 400.28 (2) angstrom3, Z = 4, D(x) = 9.28 Mg m-3, powder neutron diffraction data, lambda = 1.594 angstrom, T = 293 K, 457 reflections, R(p) = 0.048, R(wp) = 0.064, R(i) = 0.046, The lattice belongs to the CaFe2O4-type structure; it is built up from double ribbons of edge-sharing TlO6 octahedra, linked through their corners. Comparison is made with TI-O distances in other oxides and especially with high T(c) superconductors. The JCPDS File No. for SrTl2O4 is 43-1497.