SrTiO3 buffering effect on Pb1−xLaxTiO3 thin films prepared by pulsed laser deposition

Abstract

Thin films of phase-pure perovskite PLT (Pb0.95La0.05Ti0.9875O3) were deposited in situ onto Si, Pt/Ti/SiO2/Si, and SrTiO3/Si substrates by pulsed laser deposition from stoichiometric targets. No Pb loss was observed in the near-surface region. The blocking of the interdiffusion between inner Si substrate and the outer PLT films by SrTiO3 buffer layer was evidenced using x-ray diffraction (XRD) and secondary ion mass spectrometry (SIMS) analyses. The formation of TiO2 second phase in PLT/Pt/Ti/SiO2/Si films was indicated by XRD and SIMS spectra to be the outward diffusion of Ti atoms from the underlying Ti layer through the Pt layer, reacting with ambient O2 at the PLT-to-Pt interface.