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Influence of MoO3 on the Structure of Lithium Aluminum Phosphate Glasses

Saddeek Y. B., Abo-Naf S. M.

Archives of Acoustics

2012

Vol. 37, No. 3

341-347

IR spectroscopy, density and ultrasonic velocity measurements have been carried out for aluminum lithium phosphate glasses with and without MoO3. The observed changes in the FTIR spectra of the glasses were related to the modifier/former role of molybdenum ions. The results revealed that the density increases with increasing MoO3 content, which was attributed to the increase in the compactness and packing of the glass network. The ultrasonic data were analyzed in terms of creation of new bonds of MoO3 attached to phosphate units. The new bonds increased the average crosslink density and the number of network bonds per unit volume along with a strengthening of the different modes of vibrations which in its turn increased the ultrasonic velocity, the rigidity and hence the elastic moduli of the glasses.

Effect of Fly Ash on the Li2O-B2O3 System: Structural Study by Pulse Echo Technique

Saddeek Y. B., Azooz M. A., Kenawy S. H.

Archives of Acoustics

2005

Vol. 30, No. 3

357-371

Fly ash obtained from Toshkey project, which in turn was delivered from France, is a valuable source of many oxides such as SiO2, Al2O3, Fe2O3, CaO and MgO. These oxidescan provide a useful preliminary source for the preparation of glasses. Glass of the system 10 Li2O - 90 B2O3 (wt %) has been prepared. The progressive addition of ly ash to this type of glass was made to study its effect on the chemical and physical properties of the parent glass. Room temperature ultrasonic measurements were performed by pulse-echo method. The densities of the prepared samples were measured to justify the packing arrangements of the constituent oxide. The variations in densities and ultrasonic velocities of the prepared samples containing progressive fly ash contents were correlated and discussed. The values of elastic moduli (including Young's modulus, bulk modulus, shear modulus and Poisson's ratio) were compared with those theoretically calculated in terms of Makishima-Mackenzie model and a model proposed by Rocherulle et al.