Spectroscopic characterization and conductivity of Sn-substituted LiTi2(PO4)3

Sn-doped LiTi2(PO4)3 samples of composition Li[Ti2−xSnx](PO4)3 (x = 0–0.5) are prepared by solid-state reaction. XRD results are indicative of formation of phase-pure materials of rhombohedral structure with the space group R3¯c\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R\;\overline{3} \;c$$\end{document} (167). Study of the microstructure by scanning electron microscopy (SEM) revealed particle size was in the range 0.6–1 μm and that grain size decreased with increasing Sn content. Raman spectra contained peaks at high frequencies ascribed to intramolecular PO43– stretching modes. Study of electrochemical impedance up to 573 K revealed high ionic conductivity of 2.02 × 10−4 S/cm at room temperature for x = 0.1.