Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 2

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Effect of Annealing Temperature on the Electric and Dielectric Properties of Se_{70}Te_{15}Bi_{15} Films

100%
Atyia H.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 1
98-104
EN
The effect of annealing at different temperatures between T_{g} and T_{c} on the AC conductivity and dielectric properties was studied for Se_{70}Te_{15}Bi_{15} films grown by thermal evaporation technique. The films were characterized by X-ray diffraction, differential thermal analysis, and energy dispersive X-ray spectroscopy. X-ray diffraction analysis shows the occurrence of amorphous to polycrystalline transformation for films annealed at annealing temperature T_{a} ≥ 473 K. AC conductivity σ_{AC}(ω) was studied as a function of T_{a}, frequencies (0.1-100 kHz) and working temperatures (303-393 K). It was found that σ_{AC}(ω) obeyed Aω^{s} law. According to the values of s and its temperature dependence, the AC conduction mechanism was determined in terms of the correlated barrier hopping and quantum mechanical tunneling models for the as deposited and annealed films, respectively. The DC and AC activation energies were determined as a function of T_{a}. Values of dielectric constant ε_1 and dielectric loss ε_2 were found to increase with increasing T_{a}. A Debye-like relaxation of dielectric behavior was observed for polycrystalline films, and was found to be a thermally activated process.
2
Content available remote

Ac Conductivity and Dielectric Properties of Amorphous Ge_{15}Se_{60}X_{25} ( X = As or Sn) Films

51%
Hegab N., Afifi M., Atyia H., Ismael M.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 3
416-423
EN
The ac conductivity and dielectric properties of Ge_{15}Se_{60} X_{25} (X = As or Sn) thin films are reported in this paper. The thin films were deposited by thermal evaporation at 10^{-5} Torr pressure. The films were well characterized by X-ray diffraction, differential thermal analysis and energy dispersive X-ray spectroscopy. The ac conductivity was measured over temperature range 303-413 K and frequency range 10^2-10^5 Hz. The frequency dependence of the ac conductivity was found to be linear with slope which lies very close to unity and is independent of temperature. This behavior can be explained in terms of the correlated barrier hopping between centers forming intimate valence alternation pairs. Values of the dielectric constant ε_1 were found to decrease with frequency and increase with temperature. The maximum barrier height W_{m} for each sample, which was calculated from the dielectric measurements according to the Guinitin equation, agrees with the theory of hopping of charge carriers over potential barrier as suggested by Elliott in case of chalcogenide glasses. The density of localized state near the Fermi level was estimated for the studied films.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.