LiSbO2: synthesis, structure, stability, and lithium-ion conductivity.

LiSbO(2) has been synthesized using a ceramic method involving evacuated quartz tubes to ensure stoichiometry. Its structure [monoclinic, P2(1)/c; a = 4.8550(3) Å, b = 17.857(1) Å, c = 5.5771(3) Å; β = 90.061(6)°] has been determined using X-ray and neutron diffraction and refined on the basis of neutron data. The structure is significantly different from that of LiBiO(2) and contains chains of corner-linked SbO(3) trigonal pyramids, which provide a framework for the tetrahedral coordination of Li(+) ions. A layer structure results in which the Li sites are located in planes perpendicular to [010]. LiSbO(2) is stable in air up to ca. 400 °C, but at higher temperatures, oxidation to LiSbO(3) occurs as a two-stage process, with evidence for a metastable, intermediate LiSbO(2.5) phase presented. The Li(+)-ion conductivity, measured using alternating-current impedance spectroscopy, is similar to that of LiBiO(2), with a value of ca. 10(-6) S cm(-1) at 300 °C.