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

Chi-Hung Lee; Min-Yung Wang; Erdembayalag Batsaikhan; Chun-Ming Wu; Chin-Wei Wang; Wen-Hsien Li

doi:10.1021/acsomega.7b00565

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

ACS Omega. 2017 Aug 4;2(8):4227-4236. doi: 10.1021/acsomega.7b00565. eCollection 2017 Aug 31.

Authors

Chi-Hung Lee¹, Min-Yung Wang¹, Erdembayalag Batsaikhan¹, Chun-Ming Wu², Chin-Wei Wang², Wen-Hsien Li¹

Affiliations

¹ Department of Physics, National Central University, Jhongli, Taoyuan 32001, Taiwan.
² Neutron Group, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.

Abstract

A large enhancement of the Ni and Cr ferromagnetic moments under UV-light irradiation has been detected in 55 nm thick K_0.98Ni[Cr(CN)₆]_0.70[(H₂O)₆]_0.30·0.11H₂O Prussian blue analogues coated on 240 nm Rb_0.76Co[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.