Oxidation States of Chromium Dissolved in Glass Determined by X-ray Photoelectron Spectroscopy

The oxidation states of chromium dissolved in binary sodium silicate glasses were analyzed by X-ray photoelectron spectroscopy (XPS). The measured "equilibrium" Cr⁶⁺ fractions in glasses with varying Na₂O contents are shown to be in good agreement with results obtained by other techniques reported in the literature. XPS was then used to analyze the interface of a sodium silicate glass/chromium alloy (Inconel 718) seal. It is shown that Cr²⁺ and Cr³⁺ were the major chromium species dissolved in the glass interfacial region.