Journal article

Optical constants, band gap, and infrared-active phonons of (LaAlO₃)0.3(Sr₂AlTaO₆)0.35 (LSAT) from spectroscopic ellipsometry

  • Nunley, Timothy Nathan Department of Physics, New Mexico State University, Las Cruces,New Mexico USA
  • Willett-Gies, Travis I. Department of Physics, New Mexico State University, Las Cruces,New Mexico USA
  • Cooke, Jacqueline A. Department of Physics, New Mexico State University, Las Cruces,New Mexico USA
  • Manciu, Felicia S. Department of Physics, University of Texas at El Paso, El Paso, USA
  • Marsik, Premysl Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Switzerland
  • Bernhard, Christian Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Switzerland
  • Zollner, Stefan Department of Physics, New Mexico State University, Las Cruces,New Mexico USA
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    04.08.2016
Published in:
  • Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. - 2016, vol. 34, no. 5, p. 051507
English Using spectroscopic ellipsometry, the authors determined the optical constants (complex dielectric function) for (LaAlO₃)0.3(Sr₂AlTaO₆) 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
Faculty
Faculté des sciences et de médecine
Department
Département de Physique
Language
  • English
Classification
Physics
License
License undefined
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Persistent URL
https://folia.unifr.ch/unifr/documents/305252
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