Effect of alkali-earth modifier ion on electrical, dielectric and spectroscopic properties of Fe sub(2)O sub(3) doped Na sub(2)SO sub(4)-MO-P sub(2)O sub(5) glass system

• Published in: Journal of alloys and compounds Vol. 604; pp. 352 - 362
• Main Authors: Pavic, L, Mogus-Milankovic, A, Rao, P Raghava, Santic, A, Kumar, V Ravi, Veeraiah, N
• Format: Journal Article
• Language: English
• Published: 15-08-2014
• Subjects: Alloys; Dielectric properties; Disorders; Glass; Networks; Resistivity; Sodium; Spectroscopy
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2014.03.061

Sodium sulfo-phosphate glasses mixed with three different modifier oxides (MgO, CaO and BaO) and doped with 1.0 mol% of Fe sub(2)O sub(3) were synthesized. The combined analysis of optical absorption and ESR spectroscopy has indicated that the iron ions exist in both Fe super(3+) (in octahedral and/or tetrahedral) and Fe super(2+) (in octahedral) local coordination sites. The results of Raman spectral studies have shown a higher degree of disorder for BaO containing glass and electrical studies have revealed the highest electrical conductivity for this glass. This is related to the higher depolymerization of the glass network by Ba super(2+) ions owing to its larger ionic radius which in turns causes a decrease in electrostatic binding energy and strain energy for an easy passage of sodium ions. The low conductivity observed for all glasses is a result of the interaction between sodium and alkaline-earth ions which can be classified as the "mixed alkali-alkaline earth" effect.