Influence of the number of alkali cation on the photo-induced Co III Fe II ↔ Co II Fe III charge transfer in Cs x CoFe PBAs – A Co K-edge XANES study

Amélie Bordage (1) , Anne Bleuzen (1)

1 ICMMO - Institut de Chimie Moléculaire et des Matériaux d'Orsay

In CoFe Prussian Blue Analogues (PBAs), a small difference in the number of alkali cation per unit cell can lead to drastic differences in the properties of the PBA. We investigate the origin of this effect in order to be able to control it and design new functional materials for data storage devices. Here we characterize the Cs0.7Co4[Fe(CN)6]2.8 .17H2O and Cs2Co4[Fe(CN)6]3.3 . 11H2O PBAs by Co K-edge in situ XAS. For both PBAs, the photo-induced (PI)CoIIIFeII →CoIIFeIII charge transfer and the different involved states (room temperature, ground and PI) are described. In the case of the Cs0.7 PBA, the relaxation from the CoII FeIII PI state towards the CoIII FeII ground state is monitored and quantified. All the results, fully consistent with previous magnetometry and Co L 3-edge XAS studies, are discussed with respect to the electronic structure of the Co ions in the different involved states.

Mots clés: CsCoFe PBA; Alkali cation; Charge transfer; In situ XAS

Domaines: Chimie de coordination; Chimie théorique et/ou physique

Amélie Bordage, Anne Bleuzen. Influence of the number of alkali cation on the photo-induced Co III Fe II ↔ Co II Fe III charge transfer in Cs x CoFe PBAs – A Co K-edge XANES study. Radiation Physics and Chemistry, 2020, 175, pp.108143. ⟨10.1016/j.radphyschem.2019.02.002⟩. ⟨hal-02353974⟩