Volume 86, Number 2, April 2009
Article Number 27001
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 21 April 2009
EPL, 86 (2009) 27001
DOI: 10.1209/0295-5075/86/27001

High-temperature superconductivity (Tc onset at 34 K) in the high-pressure orthorhombic phase of FeSe

G. Garbarino1, A. Sow2, P. Lejay2, A. Sulpice2, P. Toulemonde2, M. Mezouar1 and M. Núñez-Regueiro2

1   European Synchrotron Radiation Facility (ESRF) - 6 Rue Jules Horowitz, BP 220, F-38043 Grenoble Cedex, France, EU
2   Institut NEEL, CNRS & Université Joseph Fourier - 25 Avenue des Martyrs, BP 166, F-38042 Grenoble Cedex 9, France, EU

received 17 March 2009; accepted in final form 31 March 2009; published April 2009
published online 21 April 2009

We have studied the structural and superconducting properties of $\beta $–FeSe under pressures up to 26 GPa using synchrotron radiation and diamond anvil cells. The bulk modulus of the tetragonal phase is 28.5(3) GPa, much smaller than the rest of Fe based superconductors. At 12 GPa we observe a phase transition from the tetragonal to an orthorhombic symmetry. The high-pressure orthorhombic phase has a higher Tc reaching 34 K at 22 GPa.

74.70.-b - Superconducting materials.
61.50.Ks - Crystallographic aspects of phase transformations; pressure effects.

© EPLA 2009