Separation of Contributions from the Ion Core and Free Charge Carriers to the Magnetic Susceptibility of an Anisotropic Semiconductor Bi2Te3–Sb2Te3 Crystal

Abstract

A technique is presented, by which the magnetic susceptibility χ_|^G of the ion core of an anisotropic semiconductor Bi₂Te₃–Sb₂Te₃ crystal is determined from experimental data on the magnetic susceptibility χ_∥ and χ_⊥ obtained with allowance for the orientation of the magnetic field vector H with respect to the trigonal C₃ axis of the crystal in accordance with the expression χ_∥/χ_⊥ = (χ_∥^eh + χ^G)/(χ_⊥^eh + χ^G).In this expression, the value of the magnetic susceptibility of free charge carriers χ_∥^eh and χ_⊥^eh depending on their effective masses m_∥^* and m_⊥^* known from the experiment is calculated within the framework of the Pauli and Landau- Peierls approaches. The found value of χ_|^Gfor Bi₂Te₃–Sb₂Te₃ crystals is in good agreement with experimental data, as well as with the estimates obtained in the framework of the Larmor approach explaining, in particular, a linear dependence of the molar magnetic susceptibility on the number of electrons in the molecule observed for a large number of compounds. The proposed technique can be extended to other anisotropic semiconductors.