Disproportionation of Qm (0 ≤ m ≤ 4) species in partially devitrified Li2Si2O5 glasses with small amounts of P2O5

• Published in: Journal of materials science Vol. 42; no. 18; pp. 7950 - 7955
• Main Authors: MORTUZA, M. G, AHSAN, M. R, DUPREE, R, HOLLAND, D
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-09-2007
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Chemical industry and chemicals; Exact sciences and technology; Glass-ceramics; Glasses; Disproportionation; Crystallization; Experimental study; Precursor; Additive; Silicon 29; Phosphorus 31; Lithium Disilicates; Manufacturing; NMR spectrum; Glass ceramics; Formation mechanism; Phosphorus oxides
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-006-1398-4

The effect of adding small amounts of P2O5 to lithium disilicate glasses resulted in the scavenging of lithium metal ions by a phosphate group, Li3PO4. As a consequence of the scavenging, the silicate network partially repolymerised. The phosphate group remained intact during heat treatment of the optically clear, X-ray amorphous and slightly nucleated base glasses. However, the relative amounts of the silicate species, Qm (m = 0-4), depended on the state of the glasses. These amounts, in the optically clear and X-ray amorphous, did not change with heat treatment but disproportionation occurred in the slightly nucleated and milky coloured glasses. The disproportionation followed the relation 2Q3 to Q2 + Q4 which was evident from the relative intensity of the different peaks. 23 refs.