الفهرس 
Model of a Random NetworkOnly 14 pages are availabe for public view
 |  | from | 146 |  |  |
| | | from | 146 | | |
Abstract
Different concentrations of bismuth oxide (x= 0, 5, 10, 15, 20, 25, 30) is added on the expense of boron oxide (B2O3) in the synthesized glassy matrix PbO with 40mole % containing fixed concentration of lead oxide. Prepared glassy samples will be investigated using the following techniques before and after being exposed to -radiation of doses 8 and 12 Mrad. The X-ray diffraction (XRD) to investigate the structure ordering or disordering, determine the formed phases and to approve amorphous phase. XRD investigations of x B2O3·(100-x) Bi2O3 system (0 ≤ x ≤ 30 mole%) showed no sharp peaks, only broad diffraction humps that confirms a short range order characteristics of amorphous glassy phase also the presence of broad humps indicate.Fourier transform infrared (FTIR) spectroscopy affirm the presence of the conventional absorption bands of borate groups. Up to 15 mole% Bi2O3, there is a shoulder in the low wavenumber region which becomes a band centered at 500 cm–1 and its area increases with increasing Bi2O3 content. This peak attributed to various modes of Bi–O binding vibration in BiO6 structural units. The formation of Bi–O–Bi bond indicates the formation of BiO6 or BiO3 units which can form bismuth rich separate phases easily in the glass that reveals a tendency of Bi2O3 to build its own network i.e. it can act as a network former and modifier, to justify the formation bonds of BO3 and BO4.Ultraviolet and visible spectroscopy (UV/Vis.) provides an understanding of the importance of optical parameters, including band gap energy (Eg) and the absorption of light energies by borate glass samples in UV and visible areas. All the prepared samples are characterized using FTIR, UV/Vis. spectroscopic techniques and XRD before and after being exposed to -radiation of doses 8 and 12 Mrad. No changes are observed in the wavenumber positions related to the function groups of the constituents after irradiation. Besides, all glasses show amorphous nature before and after irradiation indicating that samples can be used for radiation shieling.