" Study of some physicl properties for Ge-Se-X ,where X= Bi, As and Sn chalcogenide glass compositions"

Abstract

The present thesis is devoted to study the structural, dc,ac electrical properties and switching phenomenon of Ge15Se60As25, Ge15Se60Bi25 and Ge15Se60Sn25 film samples.

i)The structural properties are investigated as follows:

1- X-ray diffraction patterns XRD were used to study the structure properties of the studied thin films.

2-Differential thermal analysis DTA was carried out for the as prepared investigated compositions in powder form with a temperature rate of 10deg./min.

ii) Electrical properties were studied for the investigated thin films including:

(1) Dc conductivity: Dc measurements include the temperature, thickness and compositional dependences of the dc electrical conductivity and the calculation of dc conduction activation energy. (2) Switching phenomenon: It includes static and dynamic I-V characteristic curves, temperature and thickness dependences of the switching voltage ,determination of the switching voltage and power activation energies , and determination of the switching mechanism. (3) Ac conductivity and dielectric properties: Ac measurements include ac electrical conductivity, dielectric constant, dielectric loss as a function of both frequency and temperature.