Hydrostatic pressure investigation of the spin crossover compound [ Fe ( PM − BiA ) 2 ( NCS ) 2 ] polymorph I using reflectance detection

We investigated by diffuse reflectivity the effect of hydrostatic pressure (1-1800 bar) on the thermal spin transition of Fe ( PM − BiA ) 2 ( NCS ) 2 polymorph I, where PM = N - 2 -pyridylmethylene and BiA = 4 -aminobiphenyl. We evidenced the onset of a progressive transformation into a phase of higher cooperativity which cannot be assigned to polymorph II. This result is discussed with respect to previous pressure investigations.