Determination of the phase diagram of the electron doped superconductor Ba(Fe1-xCox)2As2
Abstract
Systematic measurements of the resistivity, heat capacity, susceptibility and Hall coefficient are presented for single crystal samples of the electron-doped superconductor Ba(Fe1-xCox)2As2. These data delineate an x-T phase diagram in which the single magnetic/structural phase transition that is observed for undoped BaFe2As2 at 134 K appears to split into two distinct phase transitions, both of which are rapidly suppressed with increasing Co concentration. Superconductivity emerges for Co concentrations above x ∼0.025, and appears to coexist with the broken symmetry state up to x ∼0.06. The optimal Tc appears to coincide with the Co concentration at which the magnetic/structural phase transitions are totally suppressed. Superconductivity is observed for a further range of Co concentrations, before being completely suppressed for x ∼0.18 and above. The form of this x-T phase diagram is suggestive of an association between superconductivity and a quantum critical point arising from suppression of the magnetic and/or structural phase transitions.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2009
- Bibcode:
- 2009APS..MARD35003C