Microwave derived monoclinic Ba1-xSnxNb2O6 materials as an alternative of ITO

Abstract

Microwave synthesis was optimized for preparing novel monoclinic Tin-doped Barium Niobate ceramics (Ba1-xSnxNb2O6; x= 0.0, 0.01, 0.05, 0.1, 0.2, 0.3) BSN. The intensity of monoclinic phase formation was observed to decrease on increasing tin as dopant indicating decreased crystallinity. Strained crystalline phase was observed in undoped sample that became severe on doping tin. Monoclinic metal alloy Sn2O3 formation was confirmed on increasing tin doping beyond 5%. Electronic configuration of tin (II) oxide supports the local site-wise monoclinic disorder in crystal structure due to sterically active lone pair. Such a disorder arranges increased number of degenerate energy states and reduce effective energy gap between conduction band minimum and valence band maximum. All BSN compositions were investigated for monoclinic phase stabilization, ultra-violet absorption, dielectric response, raman modes and type of carrier concentration along with hall resistivity. All measurements possessed inflexion corresponding to 5 atomic % tin doping indicating successful site substitution and estimated Sn2O3 metal formation beyond this. The values of reducing optical energy band gap, transparency to visible spectrum and hall resistivity indicated utility of these materials as a substitute transparent conducting oxide (TCO) for well-known indium tin oxide (ITO).