The effect of S doping on the superconductivity and nematicity transition of FeSe

Enhanced mechanical properties in oxide-dispersion-strengthened alloys achieved via interface segregation of cation dopants

“…Recently, the composite powder precursors for sintering ODS alloys were generally prepared by mechanical alloying or the wet chemical method [15][16][17][18]. For ODS steels, mechanical alloying is the most successful technology [19,20].…”

Synthesis and Characterization of Molybdenum- and Sulfur-Doped FeSe

“…The obtained mixture was cold pressed again into pellets (6 mm diameter, 1.5 mm thick, 0.4 g) using a uniaxial pressure of 10 MPa. The pellet was completely sealed inside an evacuated quartz ampoule and then heated at 650 °C for 24 h. 21 For polycrystalline FeSe doped samples with Mo and S, samples were prepared by a one-step solid-state reaction, with starting materials Fe (99.9% purity), Se (99.5% purity), S (99.5% purity), and Mo (99.9% purity, from Sigma) powders. With different molar ratios, the powders were mixed together in the agate mortars inside the glove box for more than 30 min.…”

“…%, superconductivity was suppressed. , For S-doped FeSe, under high pressure, the critical nematic fluctuations vanish, whereas magnetic order is dramatically induced. , Unlike FeSe under physical pressure, isoelectronic S substitution Se site can tune T s to a nematic critical point (NCP) at x ≈ 0.17 with abrupt change of superconductivity, but no magnetic order appears in FeSe 1– x S x single crystals under ambient pressure. Recently, by simultaneously tuning chemical and physical pressures, a strikingly enhanced T c has been obtained near both ends of the dome-shaped spin density wave (SDW) phase in FeSe 1– x S x rather than near the NCP. − There are many methods for the synthesis of FeSe materials, and these can be divided into four groups: the one step method, the flux method, the high-pressure method, and the solid-state reaction method . The third and last methods are usually used to prepare polycrystalline samples, and the others are used for single crystal preparation. , Generally, it is very difficult to prepare single crystal samples of FeSe with different ratios because of its sensitivity to stoichiometry …”

Hydrothermal Synthesis and Transport Properties of FeS1-xTex (0 ≤ x ≤ 0.15) Single Crystals

“…The nematic order is gradually suppressed by S doping in FeSe 1-x S x and a non-magnetic nematic quantum critical point (QCP) appears at x~0.17. However, these samples synthesized by chemical vapor transport (CVT) [16,17] or solid state reaction [18,19] were limited to the low sulfur content of x < 0.29, which hindered the study of high sulfur doping region. The successful synthesis of FeS single crystal by the hydrothermal method can provide reference for the growth of FeSe 1-x S x [7].…”