Detemination of the spin and orbital moment of the photo-magnetic octacyanotungstate(IV) in high-temperature photomagnets

Résumé

Coordination polymers based on octacyanotungstate(IV) and magnetically non-innocent manganese(II) complex cations establish a new class of high-temperature photomagnets with photo-induced magnetic ordering temperatures exceeding the boiling point of liquid nitrogen. In this proposal we aim to fully determine the mechanism of the reversible photomagnetic switching in these unique compounds, which seem to be associated with the reversible ligand dissociation at the tungsten center. The XAS/XMCD measurements seem to be the only technique that enables direct insight into the electronic/magnetic structure of W, where the photo-induced changes take place. The unequivocal determination of the photoswitching mechanism was not possible using other general techniques such as single-crystal and powder XRD or IR spectroscopy. The new knowledge gained through the implementation of the proposal will enable a rational approach to the design of the 2nd generation of photomagnets working at RT.