CuMo’ returns to CuMo upon irradiation in the reverse-M’MCT band. RbMnFe shows a charge transfer under (CT)-Induced phase transition from the Mn-II-Fe-III phase to the Mn-III-Fe-II phase. Irradiation with 532 nm light converts the Mn-III-Fe-II phase into the Mn-II-Fe-III phase, and we observe photodemagnetization. In contrast, irradiation of the Mn-II-Fe-III phase with 410 nm light causes the reverse phase transition. A CT-induced Jahn-Teller distortion Is responsible for this visible light-induced reversible photomagnetic effect. In the CoW system, a CT-induced spin transition causes the thermal phase transition from the Co-II-W-V phase to the Co-III-W-IV phase. Irradiation of the Co-III-W-IV phase with 840 nm light causes ferromagnetism with a T-C of 40 K and magnetic coercive field (H-c) of 12 000 Oe, but excitation of the back M’MCT (Co-II -> W-V) with 532 nm light leads to the reverse phase transition.

These examples of the photomagnetic effect have occurred by exciting MM’CT bands. In the fields of inorganic chemistry and materials science, researchers have studied extensively the photoinduced phase transitions between low-spin (LS) and high-spin (HS) transition metal ions. Recently, we have observed the first example of photoinduced spin crossover ferromagnetism with a FeNb system (T-C = 20 K and H-c = 240 Oe), in which a strong superexchange interaction between photoproduced Fe-II(HS) and neighboring paramagnetic Nb-IV operates through a CN bridge. The optical switching magnets described in this Account may lead to novel optical recording technologies such as optomagnetic memories and optical computers.

“
“Carbon is one of the essential elements in energy storage. In rechargeable lithium batteries, researchers have considered many types of nanostructured carbons, such as carbon nanoparticles, Brefeldin_A carbon nanotubes, graphene, and nanoporous carbon, as anode inhibitor bulk materials and, especially, as key components for building advanced composite electrode materials. Nanocarbons can form efficient three-dimensional conducting networks that improve the performance of electrode materials suffering from the limited kinetics of lithium storage. Although the porous structure guarantees a fast migration of Li ions, the nanocarbon network can serve as an effective matrix for dispersing the active materials to prevent them from agglomerating. The nanocarbon network also affords an efficient electron pathway to provide better electrical contacts. Because of their structural stability and flexibility, nanocarbon networks can alleviate the stress and volume changes that occur in active materials during the Li insertion/extraction process.