<p class="Pa10">Samarium monosulfide SmS (Fm3m, а = 5.967 Å, ΔЕ = 0.23 V, n = 10<sup>20</sup> cm<sup>–1</sup>, <em>σ</em><em> </em>= 500 Ω<sup>–1</sup> cm<sup>–1</sup>, <em>α</em><em> </em>= 350 μВ/K) is a thermoelectric material (Z>1) and, at the same time, a pressure-sensitive material (K≥40–50). Samarium monosulfide is a daltonide phase with a solid solution whose extent is mostly in the range of cationic vacancies: Sm<sub>1+x </sub>S<sub>1-x</sub>□<sub>2x</sub> (<em>x </em>= 0–0.035; 1750 K). The congruent melting temperature of SmS is 2475 K. In the Sm–S system, Sm<sub>3</sub>S<sub>4</sub> crystallizes from melt without change in composition. Samarium monosulfide thermally dissociates to Sm<sub>3</sub>S<sub>4</sub> and Sm. Large-scale SmS lots are produced from samarium and sulfur. Synthesis is carried out in sealed-off silica glass ampoules at 500–1350 K followed by heat treatment in tantalum crucibles at 1500–2400 K. The reaction of metal samarium with sulfur results in the formation of sulfide phases that coat the samarium surface in the following order: SmS, Sm<sub>3</sub>S<sub>4</sub>, Sm<sub>2</sub>S<sub>3</sub>, and SmS<sub>2</sub>. Subsequent annealing at 1500–1800 K provides SmS yields up to 96–97 mol %. Equilibrium minor phases for SmS are Sm<sub>3</sub>S<sub>4</sub>, Sm<sub>2</sub>О<sub>2</sub>S, and Sm. X-ray amorphous SmS was prepared by reacting organic samarium compounds with sulfur or H2S. The samarium (+2) oxidation state determines the chemical specifics of SmS. 90–120 μm SmS powders are thermally hydrolyzed starting at 600 K with Н<sub>2</sub> evolution and oxidize starting at 520 K to yield Sm<sub>3</sub>S<sub>4</sub> and then Sm<sub>2</sub>О<sub>2</sub>S phases. A 90–120 μm SmS fraction for film deposition by flash evaporation is prepared by milling annealed SmS samples. Tablets 75 mm in diameter for use in magnetron sputtering are pressed from a <60-μm fraction.</p>
Slip lines in front of a round notch tip in a pressure-sensitive material
