Anharmonicity of Lattice Vibrations in Bi2Se3 Single Crystals

Abstract

The temperature dependences of the Raman-active frequencies \(E_{g}^{2}\), \(A_{{1g}}^{2}\) in layered Bi₂Se₃ single crystals are studied. The contribution of the thermal expansion to a temperature variation in the frequencies is determined. The decay of the anisotropy of the elastic properties in layered Bi₂Se₃ single crystals due to strong spin–orbit coupling is shown. The Gruneisen-mode parameters for phonons \(E_{g}^{2}\) and \(A_{{1g}}^{2}\) are calculated. Systematic features in the dependences of vibrational frequencies on the atomic masses in layered Bi₂Te₃, Bi₂Se₃, and Sb₂Te₃ single crystals are determined.