Electronic and magnetic phase diagram of [Beta]Fe[subscript1.01]Se with superconductivity at 36.7 K under pressure

Journal Article · Fri Sep 17 00:00:00 EDT 2010 · Nat. Mater.

DOI:https://doi.org/10.1038/NMAT2491· OSTI ID:1006171

Medvedev, S; McQueen, T M; Troyan, I A; Palasyuk, T; Eremets, M I; Cava, R J; Naghavi, S; Casper, F; Ksenofontov, V; Wortmann, G; Felser, C

The discovery of new high-temperature superconductors based on FeAs has led to a new 'gold rush' in high-T{sub C} superconductivity. All of the new superconductors share the same common structural motif of FeAs layers and reach T{sub C} values up to 55 K. Recently, superconductivity has been reported in FeSe, which has the same iron pnictide layer structure, but without separating layers. Here, we report the magnetic and electronic phase diagram of {beta}-Fe{sub 1.01}Se as a function of temperature and pressure. The superconducting transition temperature increases from 8.5 to 36.7 K under an applied pressure of 8.9 GPa. It then decreases at higher pressures. A marked change in volume is observed at the same time as T{sub C} rises, owing to a collapse of the separation between the Fe{sub 2}Se{sub 2} layers. No static magnetic ordering is observed for the whole p-T phase diagram. We also report that at higher pressures (starting around 7 GPa and completed at 38 GPa), Fe{sub 1.01}Se transforms to a hexagonal NiAs-type structure and exhibits non-magnetic behavior.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE
• OSTI ID: 1006171
• Journal Information: Nat. Mater., Vol. 8, Issue 08, 2009
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
IRON SELENIDES
PHASE DIAGRAMS
PNICTIDES
SUPERCONDUCTIVITY
HIGH-TC SUPERCONDUCTORS
TRANSITION TEMPERATURE
MAGNETIC PROPERTIES
ELECTRONIC STRUCTURE
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE
CRYSTAL-PHASE TRANSFORMATIONS