Observation of the First-Order Raman Scattering in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">SrTiO</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span> Thin Films

A. A. Sirenko; I. A. Akimov; J. R. Fox; A. M. Clark; Hong-Cheng Li; Weidong Si; X. X. Xi

doi:10.1103/PhysRevLett.82.4500

Observation of the First-Order Raman Scattering in ${SrTiO}_{3}$ Thin Films

A. A. Sirenko, I. A. Akimov, J. R. Fox, A. M. Clark, Hong-Cheng Li, Weidong Si, and X. X. Xi

Phys. Rev. Lett. 82, 4500 – Published 31 May 1999

Abstract

We have studied lattice dynamic properties of ${SrTiO}_{3}$ thin films from 5 to 300 K using metal-oxide bilayer Raman scattering. First-order zone-center optical phonons, symmetry forbidden in single crystals, have been observed in the thin films, indicating strain-induced lowering of symmetry. The asymmetric line shape of the ${TO}_{2}$ phonon is interpreted as evidence for micropolar regions in the thin films, likely due to oxygen vacancies. The optical phonon lines and the asymmetry persist up to room temperature.

Received 22 September 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.4500

Authors & Affiliations

A. A. Sirenko, I. A. Akimov^*, J. R. Fox, A. M. Clark, Hong-Cheng Li^†, Weidong Si, and X. X. Xi

Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802

^*Permanent address: A. F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russia.
^†Permanent address: National Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Science, Beijing, People's Republic of China.