Transport properties and phase diagrams of FeSe1-xSx (0=x=1) single crystals

Based on the high quality FeSe1-xSx (0 <= x <= 1) single crystals synthesized via a hydrothermal method, we carried out systematic measurement of the normal state magnetoresistance and Hall effect. Through the maximum entropy mobility spectrum analysis (MEMSA), we investigate the evolution of mobility spectrum, which reflects the multi-band structures for different doping content x and temperature T. The relationships between T-c and carrier properties calculated by MEMSA, as well as bond angles and anion height calculated by first-principle method are investigated. Nonlinear to linear transition of Hall resistivity(rho(xy)(B)) is mainly attributed to the decreasing mobilities and merging of mobility peaks with the reductive x or increasing T. The relationship between Tc and carrier density n show weak interaction for the orthogonal phases when x <= 0.2, but nearly positive correlation for the tetragonal phases when x > 0.2. Bond angle as well as the Se/S anion height change almost linearly with x within the tetragonal phases, and the V-shaped relationships with Tc indicate that structural factors play a key role in the regulation of superconductivity. Our researches are helpful for understanding the multi-band and complex phase diagram of iron-based superconductors. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

Based on high quality FeSe1-xSx (0 <= x <= 1) single crystals, the evolution of the mobility spectrum and its relationship with temperature, doping content, and structural factors were investigated. The nonlinear to linear transition of Hall resistivity was attributed to changes in mobility and merging of mobility peaks. The correlation between Tc and carrier density showed weak interaction in the orthogonal phases but a nearly positive correlation in the tetragonal phases. The bond angle and anion height exhibited linear changes with doping content, and their relationship with Tc indicated the importance of structural factors in regulating superconductivity. This research contributes to the understanding of the multi-band and complex phase diagram of iron-based superconductors.