Photoinduced magnetization in molecule-based magnets K_xCo[Fe(CN)_6]_y·zH_2O (x approx = 0.31, y approx= 0.77, z approx= 3.54) and Mn(TCNE)_x·y(CH_2Cl_2) (x approx= 2)

摘要

Studies of photoinduced magnetization (PIM) in two molecule-based magnets, Prussian blue analog K_xCo[Fe(CN)_6]_y·zH_2O (x approx = 0.31, y approx= 0.77, z approx= 3.54) and Mn(tetracyanoethylene)_x·y(CH_2Cl_2) (x approx= 2), are Detailed analysis of the dc magnetization and ac susceptibility of Co-Fe Prussian blue shows that the material is in a cluster glass state, with strong indications of cooperative freezing of the spin clusters. The PIM effects in the material are described within our model of photoinduced spin-doping of a cluster glass. High-T_c magnet Mn(tetracyanoethylene)_x·y(CH_2Cl_2) (T_c = 75 K) shows a substantial increase in magnetic susceptibility upon illumination with blue light. There are indication that physical mechanism responsible for this effect is different from the one in Prussian blue analogs. The effect is reversible and the material returns to the state befoe illumination after heating to approx 350 K.