Effect of gamma irradiation on X-ray absorption and photoelectron spectroscopy of Nd-doped phosphate glass

Abstract

X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) of Nd-doped phosphate glasses have been studied before and after gamma irradiation. The intensity and the location of the white line peak of the L-edge XANES of Nd are found to be dependent on the ratio O/Nd in the glass matrix. Gamma irradiation changes the elemental concentration of atoms in the glass matrix, which affects the peak intensity of the white line due to changes in the covalence of the chemical bonds with Nd atoms in the glass (structural changes). Sharpening of the Nd 3d peak profile in XPS spectra indicates a deficiency of oxygen in the glasses after gamma irradiation, which is supported by energy-dispersive X-ray spectroscopy measurements. The ratio of non-bridging oxygen to total oxygen in the glass after gamma radiation has been found to be correlated to the concentration of defects in the glass samples, which are responsible for its radiation resistance as well as for its coloration.

Room-Temperature Synthesis of Sub-2 nm Ultrasmall Platinum–Rare-Earth Metal Nanoalloys for Hydrogen Evolution Reaction

“…The Nd 3d spectrum of PtNd/C in Figure d shows two broad peaks at ∼982.5 and ∼1004.9 eV due to 3d 5/2 and 3d 3/2 (Nd 3d spectra), respectively. The Δ E of the main peaks is 22.4 eV, which indicates that Nd exists mainly in the metal valence state . The broadening in the Nd 3d peaks is due to the overlapping of the Auger O KLL peak of oxygen .…”

“…Due to the formation of strong metal–oxygen bonds, the metallic RE phases exhibit extremely high oxygen affinity after the reduction process. The high binding energies subpeak located at 532.3 eV is usually attributed to oxygen bound in the surface species like, for instance, hydroxide- and carbon-related contaminants, adsorbed O 2 , or bridging oxygens …”

“…The ΔE of the main peaks is 22.4 eV, which indicates that Nd exists mainly in the metal valence state. 32 The broadening in the Nd 3d peaks is due to the overlapping of the Auger O KLL peak of oxygen. 33 Along with the Auger peak, two satellite peaks were observed in the high-resolution spectra of Nd.…”

“…The high binding energies subpeak located at 532.3 eV is usually attributed to oxygen bound in the surface species like, for instance, hydroxide-and carbon-related contaminants, adsorbed O 2 , or bridging oxygens. 32 As is typical for lanthanide metals, the XPS features of Gd are in general quite complex due to the presence of localized electrons in the 4f shell. The localized f-electrons couple through Russell−Saunders and spin−orbit coupling and result in a complex broad multiplet structure.…”

Efficient Preparation of Rare Earth Oxides from Back Extraction Praseodymium Neodymium Chloride by Flash Pyrolysis

“…The calcined products at 1000 °C and 1200 °C match the satellite peak of Pr 4 O 7 and Pr 2 O 3 in the literature. The spin-splitting peak Nd3d 5/2 is located at 982.5 eV in the product calcined at 1200 °C (Figure 5b), [14] corresponding to the + 3 valence of Nd. At 950 °C and 1050 °C, the position of the Nd3d 5/2 peak of the product is shifted, which should be due to insufficient Nd oxidation.…”