Compressibility and pressure-induced disorder in superconducting phase-separated Cs0.72Fe1.57Se2

Abstract

Pressure-dependent diffraction response of the superconducting phase separated Cs0.72Fe1.57Se2 has been studied using synchrotron radiation up to the pressure of 19 GPa. The main and secondary phases of Cs0.72Fe1.57Se2 have been observed in the whole pressure range. The main ordered phase has been found to undergo an order-disorder transition in the Fe-sublattice at least at P = 11 GPa with the corresponding kinetics on the order of hours. Contrary to the analogous temperature induced transition, the secondary phase has not been suppressed suggesting that its stability pressure range is higher than 19 GPa or the corresponding transformation kinetics is slower at room temperature. Together with the previously reported pressure-dependent resistivity and magnetic susceptibility measurements, this work indicates that superconductivity in the AxFe2-ySe2 (A - alkali metals) phases could be related to the Fe-vacancy ordering in the main phase.

References in corpus (8)

• Superconductivity at 32 K in single crystal Rb${}_{0.78}$Fe${}_2$Se${}_{1.78}$}
• Transport properties of the new Fe-based superconductor KxFe2Se2 (Tc = 33 K)
• Intrinsic phase separation in superconducting K0.8Fe1.6Se2 (Tc= 31.8 K) single crystals
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Cited by in corpus (5)

• High-pressure polymorphism of BaFe2Se3
• Complex biphase nature of the superconducting dome of the FeSe phase diagram
• Pressure-induced magnetic collapse and metallization of $\mathrm{TlF}{\mathrm{e}}_{1.6}\mathrm{S}{\mathrm{e}}_2$
• Formation of single-phase disordered CsxFe2-ySe2 at high pressure
• Phase separation in iron chalcogenide superconductor Rb0.8+xFe1.6+ySe2 as seen by Raman light scattering and band structure calculations