Abstract

Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

Meeting Name

International Seminar on Science and Technology of Glass Materials (2009: Mar. 16-19, Guntur, India)

Department(s)

Materials Science and Engineering

Keywords and Phrases

Biological response; Chemical bondings; Conducting glass; Crystalline networks; Crystalline phasis; Crystallized glass; Crystallized grains; Dipolar state; Electrical conductivity; Electrical polarization; Electrical property; Electron hopping; Glass matrices; Impedance spectroscopy; Iron phosphate glass; Low-to-highMixed alkali; Network modifiers; Phosphate glass

International Standard Serial Number (ISSN)

1757-8981

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2009 IOP Publishing Ltd., All rights reserved.

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