  We investigate by electrical transport the field-induced superconducting
state (FISC) in the organic conductor $\lambda$-(BETS)$_2$FeCl$_4$. Below 4 K,
antiferromagnetic-insulator, metallic, and eventually superconducting (FISC)
ground states are observed with increasing in-plane magnetic field. The FISC
state survives between 18 and 41 T, and can be interpreted in terms of the
Jaccarino-Peter effect, where the external magnetic field {\em compensates} the
exchange field of aligned Fe$^{3+}$ ions. We further argue that the Fe$^{3+}$
moments are essential to stabilize the resulting singlet, two-dimensional
superconducting state

Strongly Correlated Electrons;Superconductivity