Spectroscopic investigation of the dynamical behavior of the photoinduced phase transition ofNa0.6Co1.3[Fe(CN)

The dynamics of the photoinduced phase transition (PIPT) has been investigated for the Co-Fe cyanides film, Na0.6Co1.3[Fe(CN)6]∙4H2O , by means of the transient absorption spectroscopy. At low temperatures (≲150 K) , the compound shows the permanent PIPT from the low-spin phase [LS phase: LS Co3+ (t2g↑3t2g↓3)–LS Fe2+ (t2g↑3t2g↓3) ] to the high-spin phase [HS phase; HS Co2+ (t2g↑3t2g↓2eg↑2)–LS Fe3+ (t2g↑3t2g↓2) ]. We have found that the film shows the transient PIPT into the HS phase above ∼170 K , and the lifetime τPI of the photoinduced phase exponentially decreased from 10 ms at 170 K to ∼100 μs at 260 K . In the early stage (Δt≤200 ns) of the PIPT, we further have observed a characteristic photoinduced absorption band ( Y band) and ascribed the band to the LS Co2+ (t2g↑3t2g↓3eg↑1) state