Peculiarities of terahertz spectra of layered TlInS2 crystals

Аннотация

Vibrational spectra of TlInS₂ crystals in the terahertz frequency range (0.1–3 THz) have been obtained and analyzed. The observed low-frequency band is attributed to the libration oscillations of nanolayers (so-called boson peak). A correlation between the coherent low-frequency oscillation and a disordered character of the crystal structure is shown. A conclusion is made on the presence of a topological disorder that manifests itself on the layered subsystem level.