Partial Breakdown of the Field-induced Superconductivity by Dynamical Spin Reversal

has attracted considerable interests since the application of a sufficiently strong magnetic field usually destroys the superconducting state [1]. The origin of FISC can be explained by the Jaccarino-Peter compensation effect where the internal field, created by the Fe (III) moments, is compensated by the external field. Hence, Zeeman effect, that normally destroys the superconductivity, is suppressed under this condition [2]. To have more detailed microscopic information of the FISC state, we have employed ESR on λ-(BETS)