<title>Preparation and properties of Nb2O5-Fe2O3 sol-gel optical films</title>

Abstract

In this paper, the homogeneous and transparent Nb₂O₅(x)-(1-x)Fe₂O₃(x equals 0, 0.6, 0.7, 0.8, 0.9, 1.0) films were prepared by sol-gel dip-coating method using metal alkoxide [Nb(OC₂H₅)₅] and Fe(NO₃) 9H₂O as sol-gel precursors. Based on the reflectance spectra, the refractive indexes and thickness of the films were deduced. The electrochemical investigation of Li⁺ ions storage process in Nb₂O₅-Fe₂O₃ films has been made in a Pt/LiClO₄-PC(1M)/Nb₂O₅-Fe₂O₃ITO cell between -2.0 V and 1.0 V potential range vs SCE. The total electric charge inserted and extracted during a cycle has been determined by the cyclic voltammetries. The electric charge transition ability is mainly influenced by the composition and heat treatment temperature. In pure Nb₂O₅ system, an orthorhombic crystalline phase presents after heat treated at 560 degrees Celsius for an hour.