Quasi-two-dimensional electron gas at the epitaxial alumina/SrTiO3 interface: Control of oxygen vacancies
Abstract
In this paper, we report on the highly conductive layer formed at the crystalline γ-alumina/SrTiO3 interface, which is attributed to oxygen vacancies. We describe the structure of thin γ-alumina layers deposited by molecular beam epitaxy on SrTiO3 (001) at growth temperatures in the range of 400–800 °C, as determined by reflection-high-energy electron diffraction, x-ray diffraction, and high-resolution electron microscopy. In situ x-ray photoelectron spectroscopy was used to confirm the presence of the oxygen-deficient layer. Electrical characterization indicates sheet carrier densities of ∼1013 cm−2 at room temperature for the sample deposited at 700 °C, with a maximum electron Hall mobility of 3100 cm2V−1s−1 at 3.2 K and room temperature mobility of 22 cm2V−1s−1. Annealing in oxygen is found to reduce the carrier density and turn a conductive sample into an insulator.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 05, 2015
- Source ID
- 10.1063/1.4913860
Entities
People
- Agham Posadas
- Alexander A Demkov
- David J Smith
- Jean Jordan-sweet
- John G Ekerdt
- Kristy J Kormondy
- Martha R. Mccartney
- Nicholas Goble
- Sirong Lu
- Thong Q. Ngo
- Xuan P. A. Gao
Organizations
- Air Force Office of Scientific Research
- Arizona State University
- Case Western Reserve University
- International Business Machines Corporation (Armonk, NY)
- University of Texas at Austin