Crystallization process and electrical conductivity in vanadium borophosphate glass containing iron

✍ Scribed by I. Kashif; H. Farouk; S.A. Aly; A.A. Abdel-Rahman; A.M. Sanad; E.E. Assem

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 311 KB
• Volume: 10
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(91)90087-c

✦ Synopsis

Glasses were synthesized in the V~Os-P2Os-B203 system containing X moi.% Fe203 (X = 0, 0.5, 1, 2.5, 5 and 7.5). The prepared glasses were heat treated at 300 °C for 0.5, 1, 6, 12 and 24 h. The density and molar volume values for these glass samples were measured and calculated. The molar volume was found to decrease in the samples heat treated for a time exceeding 1 h, indicating the increase in the crystallinity of the samples during the heat treatment. The rate and the geometry of the crystallization due to the heat treatment were calculated by applying the Avrami equation. The electrical conductivity was measured for the untreated and heat-treated samples in the temperature range 30-250 °C. The conductivity results are discussed in relation to the hopping of iron and vanadate ions in different valence states and as a result of the increase in crystallinity of the samples during the heat treatment.