Magnetic Transformations in the Organic Conductor kappa-(BETS)2Mn[N(CN)2]3 at the Metal-Insulator Transition

摘要

A complex study of magnetic properties including dc magnetization, 1H NMR andmagnetic torque measurements has been performed for the organic conductorkappa-(BETS)2Mn[N(CN)2]3 which undergoes a metal-insulator transition atT_MI~25K. NMR and the magnetization data indicate a transition in the manganesesubsystem from paramagnetic to a frozen state at T_MI, which is, however, not asimple Neel type order. Further, a magnetic field induced transition resemblinga spin flop has been detected in the torque measurements at temperatures belowT_MI. This transition is most likely related to the spins of pi-electronslocalized on the organic molecules BETS and coupled with the manganese 3d spinsvia exchange interaction.