Preparation and properties of Nb2O5-Fe2O3 sol-gel optical films

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.