TY - JOUR
T1 - Ferromagnetism and its photo-induced effect in 2D iron mixed-valence complex coupled with photochromic spiropyran
AU - Kashima, I.
AU - Okubo, M.
AU - Ono, Y.
AU - Itoi, M.
AU - Kida, N.
AU - Hikita, M.
AU - Enomoto, M.
AU - Kojima, N.
PY - 2005/9/21
Y1 - 2005/9/21
N2 - Iron mixed-valence complex, (n-C3H7) 4N[FeIIFeIII(dto)3](dto = C 2O2S2), shows a spin-entropy driven phase transition called charge transfer phase transition around 120 K and a ferromagnetic transition at 6.5 K. These phase transitions remarkably depend on the hexagonal ring size in two-dimensional honeycomb network structure of [FeIIFeIII (dto)3]∞. In order to control the magnetic properties and the electronic state in the dto-bridged iron mixed-valence system by means of photo-irradiation, we have synthesized a photo-sensitive organic-inorganic hybrid system, (SP)[FeIIFe III(dto)3](SP = spiropyran), and investigated the photo-induced effect on the magnetic properties by the measurements of magnetic susceptibility, ESR, IR, UV-vis and 57Fe Mössbauer spectra. Upon UV irradiation at 337 nm, a broad absorption band between 500 nm and 600 nm appears and continuously increases with the photo-irradiation time, which implies that the UV irradiation changes the structure of spiropyran from closed form to open one in solid state. The photochromism in spiropyran changes the ferromagnetic transition temperature and the coercive force.
AB - Iron mixed-valence complex, (n-C3H7) 4N[FeIIFeIII(dto)3](dto = C 2O2S2), shows a spin-entropy driven phase transition called charge transfer phase transition around 120 K and a ferromagnetic transition at 6.5 K. These phase transitions remarkably depend on the hexagonal ring size in two-dimensional honeycomb network structure of [FeIIFeIII (dto)3]∞. In order to control the magnetic properties and the electronic state in the dto-bridged iron mixed-valence system by means of photo-irradiation, we have synthesized a photo-sensitive organic-inorganic hybrid system, (SP)[FeIIFe III(dto)3](SP = spiropyran), and investigated the photo-induced effect on the magnetic properties by the measurements of magnetic susceptibility, ESR, IR, UV-vis and 57Fe Mössbauer spectra. Upon UV irradiation at 337 nm, a broad absorption band between 500 nm and 600 nm appears and continuously increases with the photo-irradiation time, which implies that the UV irradiation changes the structure of spiropyran from closed form to open one in solid state. The photochromism in spiropyran changes the ferromagnetic transition temperature and the coercive force.
KW - Magnetic measurements
KW - Magnetic phase transition
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U2 - 10.1016/j.synthmet.2005.07.286
DO - 10.1016/j.synthmet.2005.07.286
M3 - Article
AN - SCOPUS:24644507986
SN - 0379-6779
VL - 153
SP - 473
EP - 476
JO - Synthetic Metals
JF - Synthetic Metals
IS - 1-3
ER -