Strain induced modification in physical properties of charge-ordered insulator BaBiO3 thin films

Abstract

Oriented thin films have been prepared using pulsed laser deposition technique on Si (001) and SrTiO3 (STO) (001) substrates. The surface morphologies of films grown on Si substrates are more uniform than STO substrate. Physical properties of BaBiO3 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.Oriented thin films have been prepared using pulsed laser deposition technique on Si (001) and SrTiO3 (STO) (001) substrates. The surface morphologies of films grown on Si substrates are more uniform than STO substrate. Physical properties of BaBiO3 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.