Tetragonal-To-Orthorhombic Structural Phase Transition At 90 K In The Superconductor Fe1.01se

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 nonsuperconducting Fe1.03Se does not. High resolution electron microscopy at low temperatures further reveals an unexpected additional modulation of the crystal structure of the superconducting...更多