Structure analysis of vitusite glass–ceramic waste forms using extended X-ray absorption fine structures

Vitusite glass–ceramic waste forms were developed and the local environments of the Nd3+ ions in the waste forms were analyzed using extended X-ray absorption fine structure (EXAFS) spectroscopy. A second shell was observed in the Fourier transform (FT) of the EXAFS Nd LIII-edge spectra with the formation of vitusite crystals in the glass matrix. This second shell was attributed to the presence of the Nd–P and Nd–Na ion pairs constituting the vitusite crystal. The preferred incorporation of Nd3+, P5+, and Na+ inside the crystalline phases surrounded by the glass matrix increased the chemical durability of the glass–ceramics.