Photoenhanced Ferromagnetism in High-K(+)-Containing K–Ni–Cr Prussian Blue Analogues Coated on Rb–Co–Fe Nanocubes

[Image: see text] A large enhancement of the Ni and Cr ferromagnetic moments under UV-light irradiation has been detected in 55 nm thick K(0.98)Ni[Cr(CN)(6)](0.70)[(H(2)O)(6)](0.30)·0.11H(2)O Prussian blue analogues coated on 240 nm Rb(0.76)Co[Fe(CN)(6)](0.74)[(H(2)O)(6)](0.26)·0.56H(2)O 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 NiN(6) and CrC(6) 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.