The Structural Phase Transition in FeSe (Fe1+dSe)

Abstract

In this letter we show that superconducting Fe1.01Se undergoes a structural transition at 90 K from a tetragonal to an orthorhombic phase but that non-superconducting Fe1.03Se does not. Further, high resolution electron microscopy study at low temperatures reveals an unexpected additional modulation of the crystal structure of the superconducting phase involving displacements of the Fe atoms, and that the non-superconducting material shows a distinct, complex nanometer-scale structural modulation. Finally, we show that magnetism is not the driving force for the phase transition in the superconducting phase.

5 pages, 5 figures

References in corpus (9)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Superconductivity at 27 K in tetragonal FeSe under high pressure
• Why Does Undoped FeSe Become A High Tc Superconductor Under Pressure?
• Crystal structure of the new FeSe1-x superconductor
• Neutron Studies of the Iron-based Family of High TC Magnetic Superconductors
• Pressure-Induced Effects on the Structure of the FeSe Superconductor