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Abstract The X-ray diffraction pattern of the two system Se80S20-xBx and Te80S20-xBx where (x=0,2.5,5 and B=In or As) was confirm the amorphous nature of the thin film of all samples. The addition of In or As on the expense of S confirm this result. Also, the non-uniformity of SEM micrographs confirm the amorphous nature of the samples under test. The SEM micrographs of all samples after addition of In or As on the expense of S and even the addition of Er cover layer reveals no change in the amorphous structure. The thermal differential analysis (DTA) of the system Se80Sx-20Bx proves that the glass transition range is wide. This range becomes narrow as In or As replacing partially S. The addition of In on the expense of S reduces this range to be 150C-200C. Replacing In by As this range becomes only one degree. The crystallization temperature (TC) of the sample Se80S20 was 2330C. The addition of In to Se80S20 on the expense of S reduced TC to be in the range 2060C- 2110C depending on the In ratio. Replacing In by As with the same ratio decreases TC to be 1800C and 1400C . The melting temperature range was 300C(5300C-5600C) for the sample Se80S20. This range decreased to be 15-200C as In replacing S partially. The thermal differential analysis (DTA) for system Te80S20-xBx where (x=0,2.5,5 and B=In or As) shows that the glass transition range for Te80S20was 150C(119-1340C). This range reduced to be 80C as 2.5 at % In added on the expense of S. The replacement of In by As reduced this range to be 2-30C depending on the As ratio. The crystallization temperature TC of Te80S20 was 1650C. This temperature increased to be 2770C as 2.5 at % In added on the expense of S. The replacement of In by As leads to increase Tc to be in the range 233-2500C depending on the As content. Generally, the observed shrink of the glass transition range for the two systems give chance to produce optic fiber cables in the amorphous state, saving costs. The high melting temperature (Tm) keep the optic fiber cable away from distortion under the environmental factors and earth movers. Accordingly, these cables can serve the international net communication well. The nonlinear variation of the transmission (T) and reflection (R) as a function of wavelength (ʎ) in the spectral range 200nm – 2500nm for thin film samples of the two system Se80S20-xBx and Te80S20-xBx where (x=0, 2.5, 5 and B=In or As) were recorded. The maximum transmission intensity for the system Se80S20-xBx where (x=0, 2.5, 5 and B=In or As) was 85% at visible and infrared regions. The top of the transmission peak was at the wavelength 1500nm for Se80S20 sample. The addition of 2.5 at % In on expense of S, leads to the appearance of plateau at a wavelength range 1100nm-2500nm. Increasing In content to 5 at %, shift the maximum transmission peaks toward long wavelength (Red shift) and located at wavelength 1750nm. Replacing In by As with different ratio, the maximum transmission peak suffered from blue shift. On the other hand, the reflected light intensity was 45 % for the sample Se80S20 at the locations 500nm,900nm and 2100nm. The addition of 2.5 at % In increase the reflection to 50% at the location 500nm and change to be 40% at locations 900nm and1400nm. Increasing In content to 5 at %, keep the reflected light intensity 40% at locations 900nm,1400nm and 2100nm. Replacement In by 2.5 at % As on expense of S, leads to shift the reflected peak toward short wavelength (blue shift). Increasing As content to 5 at %, increase the blue shift of the reflected light be peak to appear at the locations 700nm and 900nm with intensity 60%. The addition Er cover layer leads to appear transmission plateau with intensity 80 % for Se80S20Er and Se80S17.5In2.5Er samples and 60% for the sample Se80S15In5Er. The absorption coefficient was zero at low photon energy, high value at high photon energy, and moderate values at visible region. The addition of In or As on expense S, lead to decrease the absorption coefficient. This decrement was more detectable in case of adding As. The addition of Er cover layer leads to decrease the absorption coefficient of all sample. The zero or negative value of the extinction coefficient means that very smooth surfaces of the samples under test. The light transmission through the samples of the system Te80S20-xBx where (x=0,2.5,5 and B=In or As) is high during the infrared region. This was clear after the addition of In or As on expense of S. The addition of Er cover layer decreases the transmission light through all samples. The intensities of the light reflection peaks of the sample Te80S17.5As2.5 were 70% at the wavelength 850nm. The addition of Er cover layer increases this value. The values of the absorption coefficient were very small at infrared region, moderate at visible region and very high at ultraviolet region. The addition of Er cover layer keep this behavior as it is. The addition of In or As on expense of S, decrease the Urbach tail length and decrease the optical energy gap width. Both of Urbach tail length and optical energy gap decreased more by the addition of Er cover layer. The addition of In or As increase the refractive index of all samples. The maximum refractive index was high for Te80S17.5As2.5 before and after the addition Er cover layer. The extinction coefficient decreases in steps for all samples to zero values or less during infrared region. The microhardness of the samples of the two system Se80S20-xBx and Te80S20-xBx where (x=0,2.5,5 and B=In or As) was increased by increasing the applied test load. The addition of In or As on expense of S, keeps the microhardness behavior the same. The application of Mayer law confirms that, the microhardness of these systems follow reverse indentation size effect (RISE). This was revealed as the obtained values of Mayer exponent was greater than the value two. Using indentation induced cracking (IIC) model, ensure the generation of micro-cracks. The behavior of the calculated elastic moduli confirms these results. The Ac conductivity, dielectric constant and dielectric loss of thin film samples of two system Se80S20-xBx and Te80S20-xBx where (x=0,2.5,5 and B=In or As) were examined during the frequency range 0.1-107 Hz and the temperature range 233-363 K. The experimental results show that the Ac conductivity increases with the frequency and follows the power law σ=ωs where S<1 and the value of S decreases with increasing the temperature. The addition of In to Se80S20 sample with different ratios decreases the Ac conductivity. The same behavior of Ac conductivity is shown for samples Te80S20 and Te80S17.5As2.5. Also, the Ac conductivity of the thin films samples was increased with temperature. The dielectric constant of all samples decreases with frequency and increases with temperature The addition of In or As on the expense of S keep the dielectric constant behavior as it is, but increases its values. The dielectric loss behaves like, the dielectric constant with temperature and with frequency. Generally, the obtained unique structure, thermal stability, physical, mechanical and electric, dielectric properties supports the use of the chalcogenide material under test as optical fiber cables. |