Polarisation dependence of Schottky barrier heights at ferroelectric BaTiO3 / RuO2 interfaces: influence of substrate orientation and quality. (29th June 2016)

• Record Type: Journal Article
• Authors: Hubmann, Andreas H; Li, Shunyi; Zhukov, Sergey; von Seggern, Heinz; Klein, Andreas
• Is Part Of: Journal of physics. Volume 49:Number 29(2016)
• Publication Date: 2016-06-29
• Subjects: ferroelectric materials -- Schottky barrier -- polarisation -- photoemission -- Kolmogorov–Avrami–Ishibashi model -- BaTiO3/RuO2; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/29/295304
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: In situ x-ray photoelectron spectroscopy was employed to examine the change in Schottky barrier height Δ Φ B at BaTiO3 /RuO2 interfaces upon polarisation reversal for [1 0 0], [1 1 0] and [1 1 1] oriented BaTiO3 single crystals. Compared to previous measurements on BaTiO3 /RuO2 interfaces (Chen and Klein 2012 Phys. Rev . B 86 094105), the crystals exhibit a significantly reduced dependence of barrier height on polarisation direction. This is connected to a much higher polarisation of the present cystals, which is comparable to the accepted bulk polarisation of BaTiO3 of 26 μ C c m − 2 and which exhibit the expected dependence on crystal orientation. This indicates a much higher crystal quality in the present experiments, which is also confirmed by a Kolmogorov–Avrami–Ishibashi like polarisation switching dynamics. It is observed that Δ Φ B is reduced for the [1 1 0] and [1 1 1] orientation and scales with polarisation as long as crystals from the same batch are used. The fact, that a poor polarisation hysteresis behaviour relates to a high polarisation dependence of Schottky barrier height, indicates that the electrode's ability to screen ferroelectric polarisation charges depends sensitively on crystal and/or interface quality.