XPS examination of Cr(V) compounds

X-ray photoelectron spectroscopy (XPS) was used to study the oxidation state of Cr in Ca/sub 5/(CrO/sub 4/)/sub 3/Cl and Ca/sub 2/CrO/sub 4/Cl, which are being evaluated for use as cathodes in thermal batteries. The measured binding energies of Cr(V) in these compounds are 579.5 and 579.0 eV, respectively, which are intermediate between those for Cr(III) and Cr(VI). XPS was also evaluated as an investigative tool for monitoring the oxidation state of Cr during the discharge of Cr(V) compounds used as cathodes in thermal batteries.