MOKE magnetometry as a probe of surface magnetic impurities in electropolymerized magnetic thin films of the Prussian blue analogue Fe3[Cr(CN)6]2·15 H2O

Abstract

A magneto-optical Kerr effect (MOKE) study has been performed on electrodeposited thin films of the Prussian blue analogue Fe₃[Cr(CN)₆]₂·15H₂O (1). This study reveals the onset of hysteretic magnetic signals at temperatures above 60 K, in contrast with magnetic susceptibility measurements which indicate a Curie temperature of 23 K for this ferromagnetic film. The origin of this discrepancy is due to the presence of amorphous iron oxide particles that accumulate in the surface of the material. This report illustrates the potential of MOKE magnetometry for the detection of surface chemical impurities that remain elusive using bulk magnetic techniques.