# Anisotropy of infrared-active phonon modes in the monodomain state of tetragonal ${\mathrm{SrTiO}}_{3}$ (110)

• Yazdi-Rizi, Meghdad Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Switzerland
• Maršík, Premysl Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Switzerland
• Mallett, Benjamin P. P. Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Switzerland
2017
Published in:
• Physical Review B. - 2017, vol. 95, no. 2, p. 024105
English With infrared (IR) and terahertz (THz) ellipsometry we investigated the anisotropy of the IR-active phonon modes in ${\mathrm{SrTiO}}_{3}$ (110) single crystals in the tetragonal state below the so-called antiferrodistortive transition at T∗=105 K. In particular, we show that the anisotropy of the oscillator strength of the so-called R mode, which becomes weakly IR active below T∗, is a valuable indicator of the orientation of the structural domains. Our results reveal that a monodomain state with the tetragonal axis (c axis) parallel to the [001] direction can be created by applying a moderate uniaxial stress of about 2.3 MPa along the [1-10] direction (with a simple mechanical clamp). The resulting splitting of the IR-active phonon modes is reported.
Faculty
Faculté des sciences et de médecine
Department
Département de Physique
Language
• English
Classification
Biology