2009/03/12 by Sergey A. Medvedev, S. Medvedev, T. M. McQueen +15
Business, Management and Accounting · Chemistry · Materials Science · Physics and Astronomy · #Ambient pressure #Chemistry #Condensed matter physics #Corporate Taxation and Avoidance #Crystallography #Hexagonal crystal system #Iron-based superconductors research #Materials science #Phase (matter) #Phase diagram #Physics #Pnictogen #Superconducting transition temperature #Superconductivity #Thermodynamics #Transition temperature #cond-mat.supr-con
paper · pdf · doi:10.1038/nmat2491
published as Nature Materials 8, 630 - 633 (2009) · 17 pages, 4 figures
arxiv created 2009/03/12 · openalex publication_date 2009/06/14 · arxiv updated 2009/12/01 · openalex created_date 2017/11/10 · openalex updated_date 2026/08/05
In this letter, we report that the superconductivity transition temperature in beta-Fe1.01Se increases from 8.5 to 36.7 K under applied pressure of 8.9 GPa. It then decreases at higher pressure. A dramatic change in volume is observed at the same time Tc rises, due to a collapse of the separation between the Fe2Se2 layers. A clear transition to a linear resistivity normal state is seen on cooling at all pressures. No static magnetic ordering is observed for the whole p-T phase diagram. We also report that at higher pressure (starting around 7 GPa and completed at 38 GPa), Fe1.01Se transforms to a hexagonal NiAs-type structure and displays non-magnetic, insulating behavior. The inclusion of electron correlation in band structure caculations is necessary to describe this behavior, signifying that such correlations are important in this chemical system. Our results strongly support unconventional superconductivity in beta-Fe1.01Se.