Crystal Structure of Li_0.50Co_0.25TiO(PO₄)

抄録

Li_0.50Co_0.25TiO(PO₄) has been obtained by the conventional solid state reaction technique. Its crystal structure has been refined from X-ray powder diffraction data by the Rietveld method in P2₁/c space group (R_B=0.08, R_F=0.05, R_p=0.13 and R_wp=0.18). The monoclinic unit cell parameters are: a_m=6.400±0.001Å, b_m=7.279±0.001Å, c_m=7.385±0.001Å,β=90.36?±0.02°Z=4. The structure is formed by a three dimensional framework of TiO₆ octahedra and PO₄ tetrahedra. TiO₆ octahedra form -Ti-O-Ti-O- infinite chains parallel to the c axis. In these chains, very short Ti-O bonds (~1.68Å) and very long ones (~2.26Å) are alternating. The cobalt and lithium atoms occupy octahedral cavities which form infinite chains of edge-sharing octahedra running parallel to the a axis.