Dynamics of the charge transferred states relevant to magnetic phase transition in rubidium manganese hexacyanoferrate

Photoinduced charge transfer dynamics in the photomagnetic material RbMn[Fe(CN)6], which exhibits a magnetic phase transition with a large hysteresis loop (230-300 K), has been investigated by observing the CN− stretching modes, which are sensitive to the valences of the adjacent transition metal ions. Mid-infrared transient absorption measurements were performed between 2013 and 2179 cm−1 to observe the transient and persistent products. The sample in the high-temperature phase was excited by 400 nm laser pulses at the ligand to metal charge transfer band near the high-temperature end of the hysteresis loop. Bleach of the Fe3+-CN−-Mn2+ band representing a decrease of the high-temperature phase and increases of the Fe2+-CN−-Mn3+ and Fe2+-CN−-Mn2+ bands were observed in picosecond time region, indicating a transient production of charge transferred states.