Optical phonons in TlFeS$_{2}$, TlFeSe$_{2}$ semiconductor compounds

X-ray studies of TlFeS$_{2}$, TlFeSe$_{2}$ crystals obtained by high-temperature synthesis revealed their monophases and isostructurality with the space group of C2/m symmetry. Raman scattering and infrared reflection of light in TlFeS$_{2}$, TlFeSe$_{2}$ compounds at the temperature 300 K were investigated. The characteristic frequencies of Raman and IR-active phonons in TlFeS$_{2}$ and TlFeSe$_{2}$ have been determined. From the analysis of published works on the magnetic properties of TlFeS$_{2}$, TlFeSe$_{2}$, it was concluded that they are quasi-one-dimensional antiferromagnets, each of which has two characteristic temperatures, $T_{\mathrm{N3D}}$ and $T_c^{\operatorname{super-p}}$, between them there is a quasi-one-dimensional antiferromagnetic ordering in TlFeS$_{2}$, TlFeSe$_{2}$. The temperature $T_c^{\operatorname{super-p}}$, was introduced for the first time and characterizes a highly developed short-range magnetic order, in which superparamagnetic ordering exists.