Influence of Ag, Cd or Pb Addition on Electrical and Dielectric Properties of Bulk Glassy Se-Ge
E. G. El-Metwally; Shakra, A. M.;
Abstract
Bulk glassy samples of Se0.7Ge0.3 and Se0.7Ge0.25X0.05 (X = Ag, Cd or Pb)
chalcogenide glass have been prepared by melt-quenching method. The
studied compositions were examined in powder form by x-ray diffraction
analysis. The direct-current (dc) conductivity rdc was measured for bulk
samples in the temperature range from 303 K to 433 K, revealing enhancement
with temperature for all samples. The results indicate two values of
activation energy (DEr1 and DEr2 ) due to two conduction mechanisms. Measurements
of the alternating-current (ac) conductivity racðxÞ and dielectric
properties for bulk samples were carried out in the temperature range from
303 K to 433 K and frequency range from 1 kHz to 1 MHz. The ac conductivity
racðxÞ was temperature dependent and proportional to xS, where S is the
frequency exponent, which reduced with rising temperature, and x is the
angular frequency. These results are discussed based on a correlated barrier
hopping model. The calculated values of the maximum height of the barrier
WM for each composition are consistent with carrier hopping over a potential
barrier. The density of localized states NðEFÞ at the Fermi level lay in the
range from 1019 eV 1 cm 3 to 1020 eV 1 cm 3, and increased with temperature.
The dielectric constant e1ðxÞ and loss e2ðxÞ increased with temperature
but decreased with frequency. The values of rdc, racðxÞ, e1ðxÞ, and e2ðxÞ increased
with temperature and with addition of Ag, Cd or Pb. The observed
increase was greater for Se0.7Ge0.25Pb0.05 than for Se0.7Ge0.25Cd0.05, which was
greater than for Se0.7Ge0.25Ag0.05.
chalcogenide glass have been prepared by melt-quenching method. The
studied compositions were examined in powder form by x-ray diffraction
analysis. The direct-current (dc) conductivity rdc was measured for bulk
samples in the temperature range from 303 K to 433 K, revealing enhancement
with temperature for all samples. The results indicate two values of
activation energy (DEr1 and DEr2 ) due to two conduction mechanisms. Measurements
of the alternating-current (ac) conductivity racðxÞ and dielectric
properties for bulk samples were carried out in the temperature range from
303 K to 433 K and frequency range from 1 kHz to 1 MHz. The ac conductivity
racðxÞ was temperature dependent and proportional to xS, where S is the
frequency exponent, which reduced with rising temperature, and x is the
angular frequency. These results are discussed based on a correlated barrier
hopping model. The calculated values of the maximum height of the barrier
WM for each composition are consistent with carrier hopping over a potential
barrier. The density of localized states NðEFÞ at the Fermi level lay in the
range from 1019 eV 1 cm 3 to 1020 eV 1 cm 3, and increased with temperature.
The dielectric constant e1ðxÞ and loss e2ðxÞ increased with temperature
but decreased with frequency. The values of rdc, racðxÞ, e1ðxÞ, and e2ðxÞ increased
with temperature and with addition of Ag, Cd or Pb. The observed
increase was greater for Se0.7Ge0.25Pb0.05 than for Se0.7Ge0.25Cd0.05, which was
greater than for Se0.7Ge0.25Ag0.05.
Other data
| Title | Influence of Ag, Cd or Pb Addition on Electrical and Dielectric Properties of Bulk Glassy Se-Ge | Authors | E. G. El-Metwally ; Shakra, A. M. | Keywords | Chalcogenide glasses;ac conductivity;dielectric properties | Issue Date | 3-May-2018 | Publisher | Springer | Journal | Journal of Electronic Materials | Volume | 47 | Issue | 8 | Start page | 4663 | End page | 4671 | ISSN | 0361-5235 1543-186X |
DOI | 10.1007/s11664-018-6353-z |
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