الفهرس 
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Abstract
Glass samples of a mixed alkali borate glasses doped with cobalt oxide have been prepared by the melt quenching technique. The structural and compositional phases of the glass systems as prepared have been identified using X-Ray Diffraction (XRD). Differential Scanning
Calorimetry (DSC) and the glass transition temperatures of these samples have been found to be compositional dependent. Studying of (FT-IR) spectroscopic from 400 to 4000 cm-1 has been employed to study the role of BO3, and BO4 on the structure of these glass samples.
The density and the molar volume of these samples have been investigated. from the ultrasonic velocity measurements, the mechanical
properties and Debye temperature (θD) have been determined. Theoretical
calculations of the elastic moduli were derived from the application of the bond compression theory and Makishima – Mackenzie theoretical models.
The ultrasonic attenuation process through the temperature range
160 - 300 K was measured to give information about the glass structure.
Ultrasonic low temperature is accomplished to obtain absorption coefficient measurements. Activation energy, relaxation strength,
deformation potential and number of loss centers were calculated.
The dielectric properties in the frequency range 42 Hz to 5 MHz and temperature range 303–468 K have been studied. The ac components and activation energies have been estimated and discussed. The
temperature dependence of ac conductivity at different frequencies was analyzed using (Mott’s small polaron hopping) model and, the high
temperature Frequency exponent, S, was compared with theoretical models.