Sol-gel synthesis of LiSICON compound and their studies by X-ray powder diffraction, infrared, magnetic and impedance spectroscopy

Abstract

Compounds with the formula LiNi0.9Mn0.1PO4 (LNMP) are prepared using a sol-gel synthesis method. The compound has been structurally characterized by X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy, magnetic measurements, and electrical impedance spectroscopy. The structure of the sample was orthorhombic with the Pnma space group. The study by infrared spectroscopy reveals the existence of P-O band vibrations, is attributed to the phosphate ion PO4. The morphological characterization shows that the size of the particles is of the order of 0.29 μm. The negative Curie-Weiss temperature θCW= -49.67 K suggests an antiferromagnetic interaction between the cationic MII (M = Ni/Mn) mediated through the oxygen of the PO4 bridged ion. We performed the conductivity analysis of the sample at different temperatures and frequencies, which proves that the general conduction is predominantly by the correlated barrier hopping mechanism (CBH) model with the diffusion possibility of Li+ in tunnels along the b-direction. This 2D model of conduction agrees with the computed calculation of minimum pathway energy migration.