| Abstract
| - X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) data were used to explorethe structure of cathodically deposited thin films of nickel hexacyanoferrate (NiHCF). Thin films wereelectrodeposited on Pt substrates and analyzed in both the reduced and oxidized states and when intercalatedwith Cs+, K+, and mixtures of Cs+/K+. All experiments were performed at room temperature. XRD dataprovided lattice parameters and confirmed the cubic nature of this polycrystalline material, but it couldnot establish the exact space group from the many known to exist for this class of materials. The latticeparameter monotonically increased from ca. 10.15 to 10.21 Å as the fraction of intercalated cation wentfrom 100% K+ to 100% Cs+. EXAFS data permitted the determination of average nickel coordination, aproperty directly related to the material's refined structure. Fe and Ni K-edge data were fit using feffit2.32and FEFF7; the data were fit simultaneously in order to break the correlation between coordinationnumber and the Debye−Waller factor. This resulted in mean nickel coordination values between 4.4 and5.1 and estimated lattice parameters which are ca. 0.1 Å greater than those found from XRD, a trendindicative of local disorder within the sample.
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