Small polaron-related recombination in Ba{sub x}Sr{sub 1−x}TiO{sub 3} thin films by cathodoluminescence spectroscopy

Journal Article · Mon Mar 07 04:00:00 EST 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4943191· OSTI ID:22591419

Mikheev, Evgeny; Kajdos, Adam P. ^[1]; Janotti, Anderson ^[2]

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1. Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)
2. Materials Science and Engineering, University of Delaware, Newark, Delaware 19716-1501 (United States)

Polarons are critical to our understanding of many condensed matter systems, but are difficult to observe and characterize. By combining cathodoluminescence spectroscopy measurements with insights from first-principles calculations, we have identified transitions involving two distinct and simultaneous polaronic states in relaxed Ba{sub x}Sr{sub 1−x}TiO{sub 3} films grown by molecular beam epitaxy. These polaronic optical transitions arise from two discrete Ti-O-Ti bonding configurations simultaneously present in the system, one with a 180° bond angle and the other with buckled geometry due to octahedral tilting. By compositional modulation, we show that we can semi-quantitatively probe the population of each bonding configuration.

• OSTI ID: 22591419
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 10 Vol. 108; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOND ANGLE
CATHODOLUMINESCENCE
MOLECULAR BEAM EPITAXY
MOLECULAR BEAMS
POLARONS
PROBES
SPECTROSCOPY
THIN FILMS