Upper critical field divergence induced by mesoscopic phase separation in the organic superconductor (TMTSF)2ReO4
Résumé
Due to the competition of two anion orders, (TMTSF)2ReO 4 presents a phase coexistence between semiconducting and metallic (superconducting) regions (filaments or droplets) in a wide range of pressures. In this regime, the superconducting upper critical field for H parallel to both c* and b′ axes presents a linear part at low fields followed by a divergence above a crossover field. This crossover corresponds to the 3D-2D decoupling transition expected in filamentary or granular superconductors. The sharpness of the transition also demonstrates that all filaments are of similar sizes and self-organize in a very ordered way. The distance between the filaments and their cross sections are estimated.
Mots clés
- Phase separation
- Electric conductivity
- Filaments (lamp)
- Organic conductors
- Semiconducting organic compounds
- Superconducting materials
- Superconductivity
- Cross overs
- Upper critical fields
- Superconducting upper critical fields
- Phase coexistences
- Organic superconductors
- Mesoscopic
- Low fields
- Granular superconductors
- Crossover fields
- Cross sections