The effect of pressure on the phase diagram of the magnetic field-induced superconducting state of λ-(BETS)2FeCl4

We report the effect of a small hydrostatic pressure p congruent to 1.4 kBar Oil the temperature-magnetic field phase diagram of the organic conductor lambda-(BETS)(2)FeCl4. At zero field a first-order superconducting (T-C congruent to 5.6 K) to antiferromagnetic insulator transition (T-N congruent to 4 K) is observed. The close proximity between both phases is Suggestive of an unconventional superconducting pairing mechanism. Furthermore, the transition temperature towards the field-induced superconducting state (FISC), as well as its concomitant upper critical field, is found to increase by a factor of similar to33%. The phase diagram of the FISC state for both p = 1 Bar and 1.4 kBar are well described in terms of the Jaccarino-Peter effect if the quasiparticle nature of the charge carriers is taken into account.