Photoenhanced Ferromagnetism in High-K+-ContainingK–Ni–Cr Prussian Blue AnaloguesCoated on Rb–Co–Fe Nanocubes

摘要

A large enhancement of the Ni and Cr ferromagnetic moments under UV-light irradiation has been detected in 55 nm thick K0.98Ni[Cr(CN)6]0.70[(H2O)6]0.30·0.11H2O Prussian blue analogues coated on 240 nm Rb0.76Co[Fe(CN)6]0.74[(H2O)6]0.26·0.56H2O nanocubes. Two separate magnetic transitions were found. The one at 72 K marks the magnetic ordering of the Ni and Cr ions on the shell. A higher degree of electronic connection along the Ni–N–C–Cr–C–N–Ni chains was achieved by the incorporation of a larger amount of K⁺ ions into the voids enclosed by the NiN6 and CrC6 octahedra, which was used to understand the appearance of photoenhanced ferromagnetism in the K–Ni–Cr network. A weak moment developed in the core below 10 K, corresponding to separate ordering of the Co and Fe ions in the Rb–Co–Fe network. Photoinduced ferromagnetism of the Co and Fe ions in the Rb–Co–Fe was also detected.