Photoinduced Ferrimagnetic Systems in Prussian Blue Analogues C^I<i>_x</i>Co₄[Fe(CN)₆]<i>_y</i> (C^I = Alkali Cation). 1. Conditions to Observe the Phenomenon

TLDR

Photoinduced magnetization has recently been observed in CoFe Prussian blue analogues. The study aims to identify the conditions for photoinduced magnetization by synthesizing compounds with varying cobalt environments and examining the role of hexacyanoferrate vacancies. Three compounds with variable cobalt environments were synthesized and characterized using XANES, infrared spectroscopy, and powder X-ray diffraction. Temperature‑dependent magnetization measurements revealed that diamagnetic CoIII–NC–FeII pairs are necessary but not sufficient for photoinduced magnetization.

Abstract

Photoinduced magnetization has been recently evidenced by Hashimoto et al. in CoFe Prussian blue analogues. We synthesized three compounds with a variable cobalt environment to point out the conditions required to observe the photoinduced magnetization. Structure and electronic structure of the compounds have been investigated combining XANES, infrared spectroscopy, and powder X-ray diffraction experiments. Magnetization as a function of temperature before and after irradiation showed that diamagnetic pairs CoIII−NC−FeII are necessary for the existence of the photoinduced magnetization, but their presence is not a sufficient condition. The role of hexacyanoferrate vacancies in the phenomenon is pointed out.