Dielectric relaxation and modulus of V2O5—TeO2glasses
| Autor: | Abhai Mansingh, Michael Sayer, V. K. Dhawan |
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| Rok vydání: | 1983 |
| Předmět: | |
| Zdroj: | Philosophical Magazine B. 48:215-236 |
| ISSN: | 1463-6417 1364-2812 |
| DOI: | 10.1080/13642818308228285 |
| Popis: | The dielectric behaviour of V2O5—TeO2 glasses in the composition range 10 to 80 mol.% V2O5 is reported for the temperature region 77 to 500 K and the frequency region 0.1 to 100 kHz. The variation of dielectric constant έ’ with temperature and frequency in the region where the measured a.c. conductivity approaches the d.c. conductivity indicates a bulk dielectric relaxation. The data have been analysed in terms of conventional dipolar dielectric relaxation with a distribution of dielectric relaxation times and in terms of conductivity relaxation using dielectric modulus M* = 1/e* plots. The d.c. conductivity, dielectric relaxation and conductivity relaxation have the same activation energy of 0.21–0.42 eV for decreasing V2O5 content and a frequency factor v 0 of 5 × 1010 Hz. The difference between this value and the 1012 Hz expected for phonon frequencies is attributed to a tunnelling contribution. The dielectric modulus approach is satisfactory for electronic glasses with respect to the calculat... |
| Databáze: | OpenAIRE |
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