Role of metallic Zn and In additives in the electrical and dielectric properties of Se_{0.85}Te_{0.15} glassy alloy

Authors: JYOTI SHARMA, SANTOSH KUMAR

Abstract: In this paper we report the effect of metallic Zn and In additives on the electrical and dielectric properties of Se_{0.85}Te_{0.15} glassy system. The temperature and frequency dependence of the dielectric parameters in glassy Se_{0.85}Te_{0.15}, Se_{0.75}Te_{0.15}In_{0.10} and Se_{0.75}Te_{0.15}Zn_{0.10} alloys are studied by measuring capacitance and dissipation factor in the frequency range (1 kHz--5 MHz) and temperature range (300--350 K). Direct current (dc) measurements were also performed in the aforesaid temperature range to assess the dc conduction losses. Results are interpreted in terms of a theoretical model which is based on two electron hopping over a potential barrier and is applicable in the present case. Dielectric constant \varepsilon^{\prime}, dielectric loss \varepsilon^{\prime\prime} and loss tangent \delta are found highly frequency and temperature dependent. Dependence of electrical and dielectric parameters on the additives has also been found in the present glassy system and has been discussed in terms of electronegativity difference between the elements used in making the aforesaid glassy system.

Keywords: Chalcogenide glasses, dielectric measurements, defect states, D.C. conductivity

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