Wetting at the BaTiO₃/Pt interface

Abstract

Using density functional theory, we analyze the wetting conditions for Pt on the (001) surface of ferroelectric BaTiO3 (BTO). We estimate the surface energy of (100), (110), and (111) Pt to be 2.42, 2.49, and 2.00 J/m 2, respectively. We find the BTO surface energy to vary between 0.26 and 2.28 J/m2 depending on termination, polarization, and chemical environment. The interface energy between TiO2-terminated out-of-plane polarized BTO and (100) Pt is found to be between 1.64 and 2.62 J/m2, indicating that (100) Pt cannot wet BTO for this interface. A similar result is found for an interface with (110) Pt. Cross-sectional transmission electron microscopy of Pt films grown on BTO by molecular beam epitaxy with a low flux at high deposition temperature shows Volmer-Weber islands, consistent with first principles calculations. © 2013 AIP Publishing LLC.