Influence of the number of alkali cation on the photo-induced CoIIIFeII↔CoIIFeIII charge transfer in Csx CoFe PBAs – A Co K-edge XANES study. (October 2020)

• Record Type: Journal Article
• Authors: Bordage, Amélie; Bleuzen, Anne
• Is Part Of: Radiation physics and chemistry. Volume 175(2020:Oct.)
• Publication Date: 2020-10
• Subjects: CsCoFe PBA -- Alkali cation -- Charge transfer -- In situ XAS; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2019.02.002
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: In CoFe Prussian Blue Analogs (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 Cs 0.7 Co 4 [ Fe ( CN ) 6 ] 2.8 .17 H2 O and Cs 2 Co 4 [ Fe ( CN ) 6 ] 3.3 .11H2 O PBAs by Co K-edge in situ XAS. For both PBAs, the photo-induced (PI) Co III Fe II → Co II Fe III charge transfer and the different involved states (room temperature, ground and PI) are described. In the case of the Cs 0.7 PBA, the relaxation from the Co II Fe III PI state towards the Co III Fe II ground state is monitored and quantified. All the results, fully consistent with previous magnetometry and Co L3 -edge XAS studies, are discussed with respect to the electronic structure of the Co ions in the different involved states. Abstract : Highlights: The photoinduced charge transfer in Cs2CoFe Prussian Blue analog is not complete. The two Co II Fe III states of the Cs0.7CoFe PBA presents relevant differences. The number of alkali cation has a drastic effect on the photomagnetic properties.