R. El-Mallawany - Physics Department, Faculty of Science, Menoufia University, Menoufia, Egypt
Yasser Saddeek - Physics Department, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut, Egypt
Abdelsalam Abousehly - Physics Department, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut, Egypt
Mostafa Sidkey - National Institute for Standards, EL Haram, Giza, Egypt

This work deals with the theoretical analysis of ultrasonic relaxation in the glass system xNb۲O۵ – (۱۰۰− x) TeO۲ glasses, and ۴ ≤ x ≤۲۲.۵ mole %. The parameters of the theoretical analysis deal with the transmission of ultrasonic waves through dual-well potential. The parameters are alternate potential energy, centers of energy loss, and elongation or contraction of the two-well potential. Moreover, the deformation potential is found to be sensitive to the variations of the Nb۲O۵ content. The number of centers of energy loss is related to the elastic moduli as a function of Nb۲O۵ content. The analysis revealed a sensitive effect of variation of Nb۲O۵ contents for elongation or contraction of the dual-well potential. Due to the increase of Nb۲O۵ from ۴ to ۲۲.۵ mole %, the potential energy changed from ۴-۹۲ to ۵.۰۶ eV, longitudinal and transverse deformation potential changed from ۰.۱۸ to ۰.۳۴۶ and from ۰.۰۶ to ۰.۱۴۱ eV, respectively. The increase in the deformation potential of the presented dual-well state could be attributed to the increase of the experimental elastic parameters like Young’s and shear moduli of the present glasses.

Glasses, tellurite, Ultrasonic relaxation