Optical constants, band gap, and infrared-active phonons of (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from spectroscopic ellipsometry
Abstract
Using spectroscopic ellipsometry, the authors determined the optical constants (complex dielectric function) for (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from 0.01 to 6.5 eV. Above 0.5 eV, the data were described with a sum of two Tauc-Lorentz oscillators and two poles. A direct gap of 5.8 ± 0.1 eV was found. An Urbach tail extends to even lower photon energies and makes the crystal opaque above 4.8 eV. Using Fourier-transform infrared ellipsometry, the lattice dynamics was studied. Nine pairs of transverse/longitudinal phonons were found and attributed to disorder in the La/Sr sublattice, ordering in the Al/Ta sublattice, and two-phonon absorption.
- Authors:
-
- Department of Physics, New Mexico State University, MSC 3D, P.O. Box 30001, Las Cruces, New Mexico 88003-8001 (United States)
- Department of Physics, University of Texas at El Paso, El Paso, Texas 79968 (United States)
- Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musee 3, CH-1700 Fribourg (Switzerland)
- Publication Date:
- OSTI Identifier:
- 22592849
- Resource Type:
- Journal Article
- Journal Name:
- Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films
- Additional Journal Information:
- Journal Volume: 34; Journal Issue: 5; Other Information: (c) 2016 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0734-2101
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ABSORPTION; ALUMINATES; CRYSTALS; DIELECTRIC MATERIALS; ELLIPSOMETRY; FOURIER TRANSFORM SPECTROMETERS; INFRARED SPECTROMETERS; LANTHANUM COMPOUNDS; OSCILLATORS; PHONONS; PHOTONS
Citation Formats
Nunley, Timothy Nathan, Willett-Gies, Travis I., Cooke, Jacqueline A., Zollner, Stefan, Manciu, Felicia S., Marsik, Premysl, and Bernhard, Christian. Optical constants, band gap, and infrared-active phonons of (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from spectroscopic ellipsometry. United States: N. p., 2016.
Web. doi:10.1116/1.4960356.
Nunley, Timothy Nathan, Willett-Gies, Travis I., Cooke, Jacqueline A., Zollner, Stefan, Manciu, Felicia S., Marsik, Premysl, & Bernhard, Christian. Optical constants, band gap, and infrared-active phonons of (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from spectroscopic ellipsometry. United States. https://doi.org/10.1116/1.4960356
Nunley, Timothy Nathan, Willett-Gies, Travis I., Cooke, Jacqueline A., Zollner, Stefan, Manciu, Felicia S., Marsik, Premysl, and Bernhard, Christian. 2016.
"Optical constants, band gap, and infrared-active phonons of (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from spectroscopic ellipsometry". United States. https://doi.org/10.1116/1.4960356.
@article{osti_22592849,
title = {Optical constants, band gap, and infrared-active phonons of (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from spectroscopic ellipsometry},
author = {Nunley, Timothy Nathan and Willett-Gies, Travis I. and Cooke, Jacqueline A. and Zollner, Stefan and Manciu, Felicia S. and Marsik, Premysl and Bernhard, Christian},
abstractNote = {Using spectroscopic ellipsometry, the authors determined the optical constants (complex dielectric function) for (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.35} (LSAT) from 0.01 to 6.5 eV. Above 0.5 eV, the data were described with a sum of two Tauc-Lorentz oscillators and two poles. A direct gap of 5.8 ± 0.1 eV was found. An Urbach tail extends to even lower photon energies and makes the crystal opaque above 4.8 eV. Using Fourier-transform infrared ellipsometry, the lattice dynamics was studied. Nine pairs of transverse/longitudinal phonons were found and attributed to disorder in the La/Sr sublattice, ordering in the Al/Ta sublattice, and two-phonon absorption.},
doi = {10.1116/1.4960356},
url = {https://www.osti.gov/biblio/22592849},
journal = {Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films},
issn = {0734-2101},
number = 5,
volume = 34,
place = {United States},
year = {Thu Sep 15 00:00:00 EDT 2016},
month = {Thu Sep 15 00:00:00 EDT 2016}
}
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