الفهرس 
INTRODUCTION & REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Glasses from the system [47 P2O5 - 23 Na2O - 6 Al2O3
- (24-x) PbO- x MoO3] where x=0.5, 1, 3 %wt have been
prepared using the conventional melting at temperature
1000-1100 0C then annealed at 400 0C. Also the formed
glass samples were heat treated using three different
temperatures 350, 450 and 550 0C according to the DSC
results. The x-ray diffraction analysis showed that glass
samples are amorphous even after heat treatment. Also the
obtained XRD results showed there is no crystalline phase
observed after heat treatment. The final composition was
obtained by EDX measurements after melting process.
FTIR studies were determined before and after being
exposed to gamma radiation at different doses (2.5, 10, 50
kGy). The results of absorption measurements showed that
the main bands at 1064 and 887 cm-1 of pyrophosphate and
metaphosphate units, respectively. Also radiation showed
minor changes in the wavenumber of the IR bands. Spectral
absorbance and transmittance were recorded in the spectral
range (200- 1000 nm) to investigate the effects of different
molybdenum concentrations and gamma radiation on the
Abstract
prepared glass samples. The Absorption dispersion
parameters such as: Urbach energy and optical energy gap
for direct and indirect transition were determined. The
values of Eg lie between 2.31-4.62 ev.
The durability of the phosphate glass samples was
tested in 0.1N HCl and distilled water before and after being
radiated with 50 kGy. The chemical durability results of the
glass samples were obtained by calculating the weight loss
percentage, also the change in the values of the pH of the
corroded solution was measured. The morphology of the
surface of the glass samples were examined by SEM. The
results showed that the most durable glass sample was the
phosphate glass with 3 %Mo.
Electron spin resonance (ESR) measurements were
studied before and after being exposed to different radiation
doses (2.5, 10, 50, 80 kGy) showing that molybdenum is
found in the glass network as Mo5+ not as Mo3+. The ESR
results were supported by measuring the electrical
conductivity of the prepared glass. Electrical conductivity
was demonstrated for all glass samples before and after
Abstract
radiation. It was found that electrical conductivity in the
glass samples occurred by ionic and electronic conduction
which can be cleared by the density results. Density was
measured using Archimedes principle at room temperature
and it was found that the density decreased by increasing the
molybdenum content, also molar volume and specific
volume were calculated.
To recognize the effect of heat treatment on the
characteristic vibrational bands of the structural building
units of all the glass samples, we studied FTIR spectra at
different heat treatment temperatures (350, 450 and 550 0C).
Also studying the UV and ESR spectra after the effect of
heat treatment and changes on the glass surface that could
be illustrated by SEM images.
Key words: phosphate glass, molybdenum oxide, chemical
durability, optical measurements, ESR, electrical conductivity and
density.