Small hole polarons in rare-earth titanates

Journal Article · Mon Jun 08 04:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4922316· OSTI ID:22423750

Bjaalie, L.; Moetakef, P.; Cain, T. A.; Janotti, A.; Himmetoglu, B.; Stemmer, S.; Van de Walle, C. G. ^[1]; Ouellette, D. G.; Allen, S. J. ^[2]

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1. Materials Department, University of California Santa Barbara, California 91306-5050 (United States)
2. Department of Physics, University of California, Santa Barbara, California 91306-5050 (United States)

We investigate the behavior of hole polarons in rare-earth titanates by combining optical conductivity measurements with first-principles hybrid density functional calculations. Sr-doped GdTiO{sub 3} (Gd{sub 1−x}Sr{sub x}TiO{sub 3}) was grown by molecular beam epitaxy. We show that a feature in the optical conductivity that was previously identified with the Mott-Hubbard gap is actually associated with the excitation of a small polaron. The assignment is based on an excellent match between the experimental spectra and first-principles calculations for polaron excitation mechanisms.

• OSTI ID: 22423750
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 23 Vol. 106; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
EXCITATION
GADOLINIUM COMPOUNDS
HOLES
MOLECULAR BEAM EPITAXY
POLARONS
RARE EARTHS
STRONTIUM
TITANATES
TITANIUM OXIDES