Anisotropy of the infrared-active phonon modes in the mono-domain state of tetragonal SrTiO3 (110)

Abstract

With infrared and terahertz ellipsometry we investigated the anisotropy of the infrared active phonon modes in SrTiO3 (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 infrared active below T*, is a valuable indicator for the orientation of the structural domains. Our results reveal that a mono-domain 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 mechanical clamp). The resulting, intrinsic splitting of the infrared-active phonon modes is reported.

11 pages, 5 figures

References in corpus (4)

• Ab initio calculations of the atomic and electronic structure of CaTiO3 (001) and (011) surfaces
• Optically tuned dimensionality crossover in photocarrier-doped SrTiO${}_3$: onset of weak localization
• Electric-field-induced pyroelectric order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures
• X-ray study of structural domains in the near-surface region of SrTiO3-substrates with Y0.6Pr0.4Ba2Cu3O7$ / La2/3Ca1/3MnO3 superlattices grown on top