Thin Film of Cobalt Hexacyanocobaltate

Abstract

Prussian blue analogues (PBAs) have recently acquired a great deal of attention because of their promise in the fields of energy storage, drug delivery, thermochromic materials, magnetic materials and many more. Herein, for the first time we have fabricated high-quality thin film of cobalt hexacyanocobaltate (CoHCC) on both Au and Si substrates. This was achieved by a low cost solution-processable method involving layer-by-layer (LbL) approach. The thin film was found to be insulating in nature with the resistance of ~109 Ω. Doping by HCl vapors resulted in improved electrical conductivity of the thin film. Both the Au and Si substrates were functionalized by organic monolayers of thiol and alkene prior to the thin film deposition. FESEM and HRTEM analyses of isolated material from the thin film consistently revealed cube-like morphology. Significant difference in K+ alkali ion concentration between the thin film and bulk was detected by EDXS technique. Interestingly, appreciable difference in the intrinsic magnetic moments of thin film and bulk CoHCC was evinced by XAS and XMCD techniques.