Convergence of Plasmon and Electron Transition Energies in Crystal Bi_0.6Sb_1.4Te₃

The temperature dependences of the reflection coefficient spectra in the range of effects caused by the resonant behavior of the plasma of free charge carriers of the Bi_0.6Sb_1.4Te₃ crystal, in the temperature dependences of the magnetic susceptibility of which features are observed, are investigated. A change in the shape of the plasma edge and the resulting splitting of the peak of the energy loss function were detected, which allows us to conclude that an electron-plasmon interaction affecting the state of the electronic system has been observed.