In situ optical characterization of LaAlO3 epitaxy on SrTiO3(001)
1 Department of Physics, University of California, Davis - Davis, CA 95616, USA
2 Peter Grünberg Institute (PGI), Research Centre Jülich - D-52425 Jülich, Germany
Received: 21 November 2014
Accepted: 27 January 2015
We followed the growth of LaAlO3 (LAO) on TiO2-terminated SrTiO3(001) in situ using a combination of a special monochromatic ellipsometry at photon energy of 1.96 eV and reflection high-energy electron diffraction (RHEED). We find that the phase of the ellipsometric ratio, defined as , changes linearly with the LAO film thickness. From the 4th unit cell (uc) up to the 11th unit cell, the slope of change in Δ is different from that for the initial three unit cells and yet there is no abrupt change in Δ when the LAO thickness increases from 3 uc to 4 uc. We explore structural and electronic processes in the LaAlO3-SrTiO3system that may be responsible for such an in situ observed optical response.
PACS: 78.67.-n – Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures / 78.67.Pt – Multilayers; superlattices; photonic structures; metamaterials / 68.47.Gh – Oxide surfaces
© EPLA, 2015