Field-induced spin-crossover transition of [MnIII (taa)] studied under pulsed magnetic fields

We have performed the high-field magnetization measurements on the spin-crossover complex [MnIII (taa)] (H3 taa=tris (1- (2-azolyl) -2-azabuten-4-yl) amine) under pulsed magnetic fields. The field-induced spin-crossover transition is successfully observed. The full conversion from the low to the high spin state by external magnetic field is achieved. The obtained field-temperature phase diagram agrees with the analysis, taking into account the entropy contribution from the dynamic structural disorder in the high spin state of [MnIII (taa)], which was proposed from the recent dielectric measurement. The observed field-induced transition accompanies with large hysteresis. Measurements under the pulsed fields with different sweep rates are conducted in order to clarify the dynamic character of the field-induced spin-crossover. Strong sweep rate dependence of the hysteresis indicates that crossover of the relaxation process takes place upon increasing the sweep rate.