Strong enhancement of superconductivity in inorganic electride 12CaO·7Al2O3:e- under high pressure
Abstract
We present the results of the pressure dependence of the superconductivity of the inorganic electride 12CaO·7Al2O3:e- (C12A7:e-) single crystal through the ac-susceptibility measurement under high pressure. C12A7:e- has the cage structure and the density of states derived from the cages may play an important role in the superconductivity. The superconducting transition temperature ( T c) is ∼ 0.2 K at ambient pressure and monotonically increases up to 1.79 K at 4.7 GPa. The upper critical field H c2 and - dH c2/ dT at T c, in proportion to the density of states (DOS) at Fermi energy becomes larger under high pressure. The superconductivity in C12A7:e- is mediated by the electron-phonon interaction, and the increase of Tc with pressure may arise from a peak structure of the DOS of cage conduction band.
- Publication:
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Journal of Korean Physical Society
- Pub Date:
- August 2013
- DOI:
- 10.3938/jkps.63.477
- Bibcode:
- 2013JKPS...63..477T