Structural and thermochemical study of Na2O–ZnO–P2O5 glasses

• Published in: Journal of non-crystalline solids Vol. 390; pp. 5 - 12
• Main Authors: Omrani, Refka Oueslati, Krimi, Saida, Videau, Jean Jacques, Khattech, Ismail, El Jazouli, Abdelaziz, Jemal, Mohamed
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 15.04.2014; Elsevier
• Subjects: Calorimetric study; Chemical Sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Depolymerization; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Glass transitions; Glasses (including metallic glasses); Heat dissolution; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Material chemistry; Materials science; Nuclear magnetic resonance and relaxation; Phosphate glasses; Physics; Specific materials; Specific phase transitions; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Phosphate glasses; Depolymerization; Calorimetric study; Heat dissolution; Phosphates; Raman spectra; Fourier transform spectroscopy; Glass; Composition effect; Liquid state quenching; Raman spectroscopy; Dissolution; Glass transition temperature; Magic angle; Solid state; Crystallographic site; Structure modification; Dimers; Nuclear magnetic resonance; Fourier-transformed infrared spectrometry; Spinning; Crystal structure
• DOI: 10.1016/j.jnoncrysol.2014.02.020
• ISSN: 0022-3093

Glasses of the (50−x/2)Na2O–xZnO–(50−x/2)P2O5(3≤O/P≤3.49) and (50−x)Na2O–xZnO–50P2O5 (O/P=3) (0≤x≤33mol%) compositions were prepared using the conventional melt quenching technique. The increase of density and glass transition temperature in both series is related to the reticulation of phosphate chains. For the first series of glasses, Fourier-transformed infrared (FTIR), Raman and 31P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy revealed the decrease of Q2 tetrahedral sites and the increase of phosphate dimers (Q1), indicating the shortening of phosphate chains. For the second series, FTIR and Raman spectroscopy show only the presence of Q2 tetrahedral sites. Dissolution of these series in 4.5% weight of H3PO4 solution has been followed calorimetrically and showed that the dissolution of the first series is endothermic for the low ZnO content and becomes exothermic when x rises. This behavior is correlated to the structural modification. For the second series, the dissolution phenomenon is endothermic confirming the presence of the same structure over the whole composition range. •Zinc phosphate glasses are prepared using the conventional melt quenching technique.•Calorimetric study of these series is realized in 4.5% weight of H3PO4 solution.•For the first series, the dissolution becomes exothermic when x rises.•For the second series, the dissolution phenomenon is endothermic for all compositions.