Structural Studies of Bi2O3-NaPO3 Glasses by Solid State Nuclear Magnetic Resonance and X-ray Photoelectron Spectroscopy

Glasses in the system xBi(2)O(3)-(100 - x)NaPO3 were prepared using transitional melting quenching and characterized using solid state nuclear magnetic resonance (SSNMR), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FT-IR). The addition of Bi2O3 results in the depolymerization of the phosphorus chain and the formation of Q((n)) (n = 0, 1, 2) phosphorus species, where n represents the number of P-Q-P bonds that can be quantified using P-31 magic angle spinning (MAS) NMR and constant-time double-quantum based,dipolar recoupling effects nuclear alignment reduction (CT-DQDRENAR). The Na-23{P-31}, P-31{Na-23}, and XPS results, consistently prove that both Na+ and Bi3+ ions are bounded by phosphorus tetrahedron [PO4](3-). Unlike other trivalent ions such as Ga3+ and Al3+, which connect with the phosphorus tetrahedron by corner-sharing, Bi3+ ions were first proved to share edge with the phosphorus tetrahedron by the analysis of P-31 spectra, taking the charge balance,and bond valence consideration into account. Such a difference in connectivity result in significant structural differences.