Structural, magnetic, and thermal properties of the compound Tb$_{0.8}$Sm$_{0.2}$Fe$_{2}$ with a Laves phase structure

A comprehensive study of the structure, phase composition, features of the surface topology, the magnetostrictive and thermal properties of the Tb$_{0.8}$Sm$_{0.2}$Fe$_{2}$ compound are performed. The structural features were established at micro- and nanoscale levels, and information on the magnetic domains structure at room temperature was obtained. The results of X-ray diffraction studies in a wide temperature range of 90–760 K, including Curie temperature, are represented. Experimental data on thermal expansion and magnetostriction in magnetic fields up to 12 kOe were obtained and analyzed. Anomalies were found in the thermal expansion curves $\Delta l/l (T)$ and magnetostriction $\lambda (T)$ at low temperatures. It is established that in compound under study the value of the magnetostrictive effect remains almost unchanged in a wide temperature range 100–300 K in fields up to 3.5 kOe.