Temperature and pressure evolution of the crystal structure of Ax(Fe1-ySe)2 (A = Cs, Rb, K) studied by synchrotron powder diffraction

Abstract

Temperature-dependent synchrotron powder diffraction on Cs0.83(Fe0.86Se)2 revealed first order I4/m to I4/mmm structural transformation around 216°C associated with the disorder of the Fe vacancies. Irreversibility observed during the transition is likely associated with a mobility of intercalated Alkali atoms. Pressure-dependent synchrotron powder diffraction on Cs0.83(Fe1-ySe)2, Rb0.85(Fe1-ySe)2 and K0.8(Fe1-ySe)2 (y ~ 0.14) indicated that the I4/m superstructure reflections are present up to pressures of 120 kbar. This may indicate that the ordering of the Fe vacancies is present in both superconducting and non-superconductive states.

11 pages, 5 figures, 1 table

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Cited by in corpus (11)

• Phase relations in K_xFe_{2-y}Se_2 and the structure of superconducting K_xFe_2Se_2 via high-resolution synchrotron diffraction
• The intercalation chemistry of layered iron chalcogenide superconductors
• Intrinsic crystal phase separation in antiferromagnetic superconductor RbyFe2-xSe2: a diffraction study
• Interplay between Superconductivity and Magnetism in Rb0.8Fe1.6Se2 under Pressure
• Coexistence of different electronic phases in the K0.8Fe1.6Se2 superconductor: a bulk-sensitive hard x-rays spectroscopy study
• Phase co-existence and structured diffuse scattering seen by X-ray 3D mapping of reciprocal space for Cs0.8Fe1.6Se2
• Interplay of the electronic and lattice degrees of freedom in A_{1-x}Fe_{2-y}Se_{2} superconductors under pressure
• High-pressure study of superconducting and non-superconducting single crystals of the same nominal composition Rb0.8Fe2Se2
• Compressibility and pressure-induced disorder in superconducting phase-separated Cs0.72Fe1.57Se2
• Structure, superconductivity, and magnetism in Rb1-xFe1.6Se2-zSz
• Formation of single-phase disordered CsxFe2-ySe2 at high pressure