الفهرس 
List of AbbreviationsOnly 14 pages are availabe for public view
 |  | from | 146 |  |  |
| | | from | 146 | | |
Abstract
Aim of the work: Nuclear magnetic resonance spectroscopy concerning 11B, 29Si and 23Na has been carried out to offer specific information about short-range ordered structure of borosilicate glasses. NMR results give detailed information on Si/B mixing in sodium borosilicate glasses. Our results shows that B4 is strongly associated with silicate units. The nonring B3 undergoes random mixing and ring B3 tends to connect to borate groups. The results of this study showed: The structural features of borosilicate glass with addition of different type of glass constituents (referring here to Na2O, Al2O3 and CeO2) have been shown to depend on the field strength (i.e. charge/ radius) of the cation introduced. It is showed that in glasses containing alumina or ceria or both, an increased BO fraction is induced with increase in CeO2/Na2O ratio. These features are correlated to the higher field strength of the Ce2+ as compared to Na+ cation. As a result, some of modifier Na2O are preferentially associated with the higher field strength cation Ce2+ and as a result CeO4 as a glass former unit is the product which in turn reduces NBO concentration. In this study: NMR, FTIR, XRD, EDP studies of the present complex glasses are based on investigating all types of materials constituting the network of the glasses. In this respect,23Na,29Si , 27Al and 11B NMR measurements have been carried out to obtain deeper insight into the structure of a given glass. As a result, the number of bridging (BO) and non- bridging oxygen (NBO) atoms as well as the structural role of each element can simply be determined. The NMR results also make a distinction between symmetric (B3 with 3BO or 3NBO) and asymmetric (B3 with one or two NBOs) boron, respectively B3s and B3a. The results showed: concentrated on an investigation of the magnetic properties of cerium borosilicate glass system. The relationship between the precipitates phases and magnetic clusters which determine the magnetic parameters of the initial precipitated phase has been clarified. The prepared samples were amorphous and macroscopically homogeneous except glasses of low CeO2. At the low CeO2 concentration, some of crystalline phases Na2SiO3, is evidenced. Presence of these crystalline species is further confirmed by means of XRD and EDP measurements.