Properties and Structure of Sodium-iron Phosphate Glasses

Abstract

Selected properties of phosphate glasses, containing from 14 to 43 mol% Fe2O3 and up to 13 mol% Na2O, have been measured. With increasing Fe2O3 and Na2O content, the density and dilatometric softening temperature increased, whereas, the thermal expansion coefficient and dissolution rate in water or saline at 90°C decreased. Glasses containing more than 25 mol% Fe2O3 had an exceedingly good chemical durability. Their dissolution rate at 90°C in distilled water or in saline solution was up to 100 times lower than that of window glass. Mössbauer and X-ray photoelectron spectroscopy indicate that iron(II) and iron(III) were both present in the glasses and the chemical durability improved with increasing iron(III) concentration. The outstanding chemical durability of these glasses was attributed to the replacement of P-O-P bonds by more chemically resistant P-O-Fe(II) and P-O-Fe(III) bonds.

Department(s)

Materials Science and Engineering

Second Department

Chemistry

International Standard Serial Number (ISSN)

0022-3093; 1873-4812

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1997 Elsevier, All rights reserved.

Publication Date

01 Jan 1997

Link to Full Text

Share

 
COinS