Effect of alkali cations on the photomagnetic behavior of CoFe Prussian blue analogue nanoparticles embedded in ordered mesoporous silica

Abstract The size of CoFe Prussian blue analogue nanoparticles containing either rubidium or cesium cations was controlled by their formation through a nucleation process inside the calibrated pores of an ordered mesoporous silica matrix. The corresponding references were synthesized in powder form using the same ratio between the metal species in the reaction solution. The obtained samples were characterized via infrared (IR) spectroscopy, X-ray diffraction, and magnetometry to understand the differences arising from the size reduction and the nature of the inserted alkali cation. We were able to show that the nature of the cation has a significant influence on the photoswitching properties at the macroscale in the powders. However, on the nanoscale, the influence of the surface contribution becomes more prominent and cooperative effects disappear, resulting in a new role of the alkali cation in the photomagnetic properties.