Correlation of the Optical and Magnetic Properties of Bi₂Te₃–Sb₂Te₃ Crystals

The magnetic and optical properties of Bi₂Te₃–Sb₂Te₃ crystals are investigated depending on the ratio of Bi₂Te₃ and Sb₂Te₃ components in the solid-solution composition and temperature. The results make it possible to affirm that an abrupt decrease in the magnetic-susceptibility anisotropy at T = 293 K is observed for samples, in which the electron–plasmon interaction is observed according to the data of optical studies. This is caused by the approaching energies of the plasmon and band-to-band transition which form the fundamental-absorption edge.