Strain induced modification in physical properties of charge-ordered insulator BaBiO_3 thin films

摘要

Oriented thin films have been prepared using pulsed laser deposition technique on Si (001) and SrTiO_3 (STO) (001) substrates. The surface morphologies of films grown on Si substrates are more uniform than STO substrate. Physical properties of BaBiO_3 thin films have been studied using Raman and x-ray photoelectron spectroscopic (XPS) techniques. Room temperature Raman spectroscopy confirms the presence of charge-ordering both in bulk and thin films. Our XPS results however show that the charge-disproportionation of Bi oxidation state (4-δ) and (4+δ) with δ<1 in bulk has been modified in thin films to δ=1.