%0 Journal Article
%T Structural Studies on Ag<sub>2</sub>O-P<sub>2</sub>O<sub>5</sub> Glasses
%A Gomaa El-Damrawi
%A Abdelmajued Hassan
%A Hamdy Doweidar
%A Ahamed Shaboub
%J New Journal of Glass and Ceramics
%P 77-89
%@ 2161-7562
%D 2017
%I Scientific Research Publishing
%R 10.4236/njgc.2017.73007
%X Silver phosphate glasses of general formula xAg2O¡¤(100
- x)P2O5 have been investigated over compositional
range from x = 40 to 62.5 mol%. The local structure around
phosphorus atom has been studied via 31P nuclear magnetic
resonance. The distribution of [PO4]Qn species
as a function of composition has been shown to slightly deviate from the simple
binary alkali phosphate model. An anomalous behavior has been recorded and
interpreted in terms of mixed ring-chain effect in metaphosphate composition.
The splitting of NMR spectra into sub resonances is assigned to different
binding sites characterizing Q1 ring and Q1 chain
structure. Higher Ag2O concentration (¡Ý50 mol%) leads to formation
of phosphate groups with specific resonance peaks which are mainly related to
pyro and orthophosphate species. The rate of change of the chemical shift of
the 31P NMR depends on the bond type, which in turn reflects
the extent of double bonding between phosphorus and oxygen
%K Nuclear Magnetic Resonance
%K Chemical Shift
%K Phosphate Species
%K Orthophosphates
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=77486