Mechanism of hopping conduction in Be–Fe–Al–Te–O semiconducting glasses and glass–ceramics

• Published in: Journal of materials science Vol. 57; no. 3; pp. 1633 - 1647
• Main Authors: Wójcik, Natalia A., Tagiara, Nagia S., Möncke, Doris, Kamitsos, Efstratios I., Ali, Sharafat, Ryl, Jacek, Barczyński, Ryszard J.
• Format: Journal Article
• Language: English
• Published: New York Springer US 2022; Springer; Springer Nature B.V
• Subjects: Aluminum compounds; Aluminum oxide; Basicity; Beryllium; Ceramic materials; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Conductivity; Crystallites; Crystallography and Scattering Methods; Electric properties; Electrical properties; Energy; Frequency ranges; Glass ceramics; Glass Technology; Glasteknologi; Hopping conduction; Ion concentration; Iron oxides; Lasers; Materials Science; Polarons; Polymer Sciences; Quantum mechanics; Solid Mechanics; Tellurium dioxide; Temperature dependence; Valence
• ISSN: 0022-2461; 1573-4803; 1573-4803
• DOI: 10.1007/s10853-021-06834-w

Electrical properties of beryllium-alumino-tellurite glasses and glass–ceramics doped with iron ions were studied using impedance spectroscopy. The conductivity was measured over a wide frequency range from 10 mHz to 1 MHz and the temperature range from 213 to 473 K. The D.C. conductivity values showed a correlation with the Fe-ion concentration and ratio of iron ions on different valence states in the samples. On the basis of Jonscher universal dielectric response the temperature dependence of conductivity parameters were determined and compared to theoretical models collected by Elliott. In glasses, the conduction process was found to be due to the overlap polaron tunneling while in glass–ceramics the quantum mechanical tunneling between semiconducting crystallites of iron oxides is proposed. The D.C. conductivity was found not to follow Arrhenius relation. The Schnakenberg model was used to analyze the conductivity behavior and the polaron hopping energy and disorder energy were estimated. Additionally, the correlation between alumina dissolution and basicity of the melts was observed.