We have performed 1H and 77Se NMR measurements on a π-d organic metal λ-(BEDT-TSF)2FeCl4 containing paramagnetic ions Fe3+. It is found from 1H NMR measurements that the resonance line starts to split around TFM=70K, just a temperature where a ferroelectric-like transition occurs, and with further decreasing temperature, the spectrum becomes significantly broad near the metal-insulator transition TMI=8.3K. From 77Se NMR measurements, near the phase boundary between the forced-ferromagnetic metallic state and the canted antiferromagnetic insulating state at 1.6K and 11.67T, a single peak becomes split with two new peaks emerging at the both sides of the zero-shift.
- Antiferromagnetic order
- Ferroelectric-like transition
- H and Se NMR
- Metal-to-insulator transition