Synthesis, Structure, and Phase Diagram of Iron-Based Superconductors: Bulk

Synthesis and Characterization of Molybdenum- and Sulfur-Doped FeSe

“…%, 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 …”

“… 16 − 22 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. 17 The third and last methods are usually used to prepare polycrystalline samples, and the others are used for single crystal preparation. 18 , 19 Generally, it is very difficult to prepare single crystal samples of FeSe with different ratios because of its sensitivity to stoichiometry.…”