Preparation of ferroelectric BaTi2O5 thin films on Pt(1 1 1)/Ti/SiO2/Si substrates by pulsed laser deposition

Abstract

Ferroelectric BaTi2O5 thin films were prepared on Pt(111)/Ti/SiO2/Si substrates by pulsed laser deposition under different substrate temperatures (Tsub=923–973K) and oxygen partial pressures (PO2=7.5–15 Pa). The effects of Tsub and PO2 on the phase, orientation and surface morphology of the as-deposited films were investigated. It was found that the crystallographic orientation of BaTi2O5 thin films strongly depended on Tsub and PO2. The BaTi2O5 film with the highest (020)-texture coefficient (TC(020)=0.78) was obtained at Tsub=943K and PO2=12.5 Pa, showing a higher degree of b-axis orientation as compared with those deposited under other parameters. The ferroelectric property of the BaTi2O5 thin films was then investigated and the polarization–electric field (P–E) loop was measured for the first time. The room temperature remanent polarization and coercive electric field of the BaTi2O5 thin film with a higher degree of b-axis orientation were 0.77×10−2Cm−2 and 1×106Vm−1, respectively.