Single Crystal Growth and Pressure Effect on Superconductivity of $$\hbox {FeSe}_{\mathrm{1-x}} \hbox {S}_{\textrm{x}}$$

Abstract $$\hbox {FeSe}_{\mathrm{1-x}} \hbox {S}_{\textrm{x}}$$ FeSe 1 - x S x is known to have a characteristic phase diagram where superconducting (SC), nematic and antiferromagnetic (AFM) phases coexist or compete to each other. We report single crystal growth of $$\hbox {FeSe}_{\mathrm{1-x}} \hbox {S}_{\textrm{x}}$$ FeSe 1 - x S x and pressure effect on superconductivity for the specimens with x =0.02 through the measurements of DC magnetization ( M ) and electrical resistivity ( $$\rho$$ ρ ) as a function of temperature ( T ). Single crystals of $$\hbox {FeSe}_{\mathrm{1-x}} \hbox {S}_{\textrm{x}}$$ FeSe 1 - x S x ( $$x\le 0.17$$ x ≤ 0.17 ) with a maximum dimension of 1.5 $$\times$$ × 1.5 $$\hbox {mm}^2$$ mm 2 were successfully obtained by a chemical vapor transport method. The M ( T ) and $$\rho$$ ρ ( T ) measurements have revealed that a nematic phase is suppressed and disappears at $$\sim$$ ∼ 1.5 GPa, where superconducting transition temperature $$T_{\textrm{c}}$$ T c shows a local minimum, while AFM phases appear separately inside and outside the nematic phase. A crossover of superconductivity near the end point of AFM phase reported in our previous study for $$x\ge 0.04$$ x ≥ 0.04 was not observed for x =0.02.