Abstract
High pressure electrical resistivity and x-ray diffraction experiments have been performed on Fe single crystals. The crystallographic investigation provides direct evidence that in the martensitic transition at 14 GPa the become the directions. During a pressure cycle, resistivity shows a broad hysteresis of 6.5 GPa, whereas superconductivity, observed between 13 and 31 GPa, remains unaffected. Upon increasing pressure an electronic instability, probably a quantum critical point, is observed at around 19 GPa and, close to this pressure, the superconducting and the isothermal resistivity ( K) attain maximum values. In the superconducting pressure domain, the exponent of the temperature power law of resistivity and its prefactor, which mimics , indicate that ferromagnetic fluctuations may provide the glue for the Cooper pairs, yielding unconventional superconductivity.
- Received 11 June 2013
DOI:https://doi.org/10.1103/PhysRevB.88.054110
©2013 American Physical Society