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http://nopr.niscpr.res.in/handle/123456789/29765| Title: | Structure dielectric and AC conduction properties of thermally evaporated Se30Te70 thin films |
| Authors: | Balasbramaniama, T Narayandass, Sa K Mangalaraj, D |
| Issue Date: | Dec-1997 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Thin films of Se30Te70 are prepared by thermal evaporation onto well cleaned glass substrates at 2.7 mPa. The thicknesses of the films are measured by the Tolansky technique (Fizeau fringes) and are 81 and 138 nm respectively. The X-ray diffractogram shows that the as - deposited films are polycrystalline in nature. Annealing is found to improve the dielectric properties. The capacitance (C) and loss factor (tan δ) are measured from 303-443K in the frequency range 1 kHz-1 MHz. Capacitance decreases with increasing film thickness and applied frequency, while it increases with increase of temperature. The loss factor which shows a pronounced minimum with frequency, increases with the rise of temperature and (tan δ)min shifts to a higher frequency. The large values of capacitance and dielectric constant (ϵ’) in the low frequency region indicate the possibility of an interfacial polarization mechanism. The dielectric relaxation phenomenon in these films is explained on the basis of dipolar reorientation. The activation energy calculated from the relaxation process is 0.094 and 0.23 eV at low and higher temperatures respectively. The frequency dependence of conductivity and the low value of the activation energy suggest that the conduction mechanism is due to electronic hopping. |
| Page(s): | 287-292 |
| ISSN: | 0975-1017 (Online); 0971-4588 (Print) |
| Appears in Collections: | IJEMS Vol.04(6) [December 1997] |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJEMS 4(6) 287-292.pdf | 841.88 kB | Adobe PDF | View/Open |
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