Point defect distribution in high-mobility conductive SrTiO3 crystals

Scientific paper - Original scientific paper

• Author: A. Gentils
• Author: O. Copie
• Author: G. Herranz
• Author: F. Fortuna
• Author: M. Bibes
• Author: K. Bouzehouane
• Author: E. Jacquet
• Author: C. Carretero
• Author: Mario Basletić
• Author: Emil Tafra
• Author: Amir Hamzić
• Author: A. Barthelemy
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

We have carried out positron annihilation spectroscopy to characterize the spatial distribution and the nature of vacancy defects in insulating as-received as well as in reduced SrTiO3 substrates exhibiting high-mobility conduction. The substrates were reduced either by ion etching the substrate surfaces or by doping with vacancies during thin film deposition at low pressure and high temperature. We show that Ti-vacancies are native defects homogeneously distributed in as-received substrates. In contrast, the dominant vacancy defects are the same both in ion-etched and substrates reduced during the film growth, and they consist of non-homogeneous distributions of cation-oxygen vacancy complexes. Their spatial extension is tuned from a few microns in ion-etched samples to the whole substrate in specimens reduced during film deposition. Our results shed light on the transport mechanisms of conductive SrTiO3 crystals and on strategies for defect-engineered oxide quantum wells, wires and dots.

• Keywords (english): positron annihilation; point defects; defect clusters; ion radiation effects
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical review B: Condensed matter and materials physics
• Numbering: vol. 81, no. 14, 144109
• p-ISSN: 1098-0121
• e-ISSN: 1550-235X
• DOI: https://doi.org/10.1103/PhysRevB.81.144109
• URN:NBN: urn:nbn:hr:217:711002
• Publication: 2010
• Project: Number: 119-1191458-1023; Title (croatian): Sustavi s prostornim i dimenzijskim ograničenjima: korelacije i spinski efekti; Leader: Amir Hamzić; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://link.aps.org/doi/10.1103/PhysRevB.81.144109
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2010) by the American Physical Society. Received 20 January 2010; revised manuscript received 8 March 2010; published 13 April 2010.
• Created on: 2019-11-02 17:35:49