Effect of oxygen partial pressure on structure and dielectric property of BaTi2O5 films prepared by laser ablation

Abstract

BaTi2O5 ferroelectric films were prepared on MgO (100) substrates by laser ablation at various oxygen partial pressures (P O2). The effect of PO2 on the orientation, composition, surface morphology and dielectric property of the films was investigated. The molar ratio of Ti to Ba was independent of PO2, almost in agreement with the stoichiometric composition of BaTi2O5. The BaTi2O5 films showed the orientation of (710) and (020) depending on PO2. At PO2 = 12.5 Pa, (020) oriented BaTi2O5 film with an elongated granular and perpendicularly crossing texture was eoitaxiallv grown on MgO (100) substrates. The BaTi2O5 film prepared at PO2 = 12.5 Pa exhibited a sharp permittivity maximum ε′ ≈ 2000) at 750 K. © 2007 The Japan Institute of Metals.