Session R41: Focus Session: Dielectric, Ferroelectric, and Piezoelectric Oxides IV
2:30 PM–5:30 PM, Wednesday, March 15, 2006
Baltimore Convention Center Room: 344
Sponsoring Unit:
DMP
Chair: Maitri Warusawithana, Penn State University
Abstract ID: BAPS.2006.MAR.R41.3
Abstract: R41.00003 : Coverage and bonding of thin, buried epitaxial SrTiO$_{3}$ on Si(100)
2:54 PM–3:06 PM
Authors:
Lena Fitting
(Applied and Engineering Physics, Cornell University)
Venugopalan Vaithyanathan
(Department of Material Science and Engineering, Pennsylvania State University)
Melanie Jones
(Applied and Engineering Physics, Cornell University)
Darrell G. Schlom
(Department of Material Science and Engineering, Pennsylvania State University)
David A. Muller
(Applied and Engineering Physics, Cornell University)
SrTiO$_{3}$ can be used as a buffer layer for the growth of perovskite oxide heterostructures, opening up possibilities for the incorporation of novel materials into existing Si-based technology. While these layers have been studied during growth, a serious question for such thin layers is if their structure remains unaltered after they have been overgrown. Here, we present results of thin SrTiO$_{3}$ films grown on Si(100). Scanning transmission electron microscopy (STEM) of the buried structures shows the formation of islands and a non-uniform coverage of the first few monolayers after capping with a-Si. The island size increases if the SrTiO$_{3}$ film is grown on a SrSi$_{x}$ seed. An important question that arises is the existence of oxygen vacancies at the interface between the oxide and the substrate. Oxygen deficiency leads to a doping of the empty Ti 3d band in bulk SrTiO$_{3}$ with electrons, thereby inducing a metallic phase as the Ti formal valence changes from 4+ to 3+. Using electron energy loss spectroscopy in a STEM the Ti valence across the interface is probed on the atomic scale.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2006.MAR.R41.3