High-energy X-ray diffraction study of Ni-doped sodium metaphosphate glasses

Abstract The structures of four Ni-doped sodium metaphosphate glasses (NiO) x (NaPO 3 ) 1− x [ x  = 0.009, 0.018, 0.033 and 0.074] were investigated by high-energy synchrotron X-ray diffraction ( E  = 120.0 keV). With increasing NiO content the development of the first nickel–oxygen correlation could clearly be observed in the corresponding pair correlation functions. The high-resolution X-ray diffraction data enabled the separation of the first Ni–O, Na–O and O–O correlations for a-(NiO) 0.074 (NaPO 3 ) 0.926 . The first average Ni–O distance is 2.02(2) A and the coordination of Ni with O, which was also determined by EXAFS at the Ni K-absorption edge, is 6. Interatomic distances between phosphorus and bridging (P–O B ) or non-bridging oxygen (P–O T ) could be discriminated in the structures of all investigated samples.