الفهرس 
Tellurite crystals and glassesOnly 14 pages are availabe for public view
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Abstract
This study presents an investigation of tellurite glasses and starts with the
binary and ternary undoped tellurite glasses to study the effect of the modifier on
tellurite network. Then to investigate how the structural changes affect the
spectroscopic properties of rare earth ions incorporated in the glass network aiming
for possible application as WLEDs. A detailed study about physical, structural,
thermal and optical properties of binary magnesium tellurite ( xMgO-(100-x)TeO2),
x= 10, 15, 20......45 mol% of MgO), binary borotellurite (xB2O3-(100-x) TeO2,
x=10, 20, 30 mol%) and ternary magnesium borotellurite (70TeO2 - (30-x)B2O3 -
xMgO, x= 5, 10, 15,....25 mol%) glasses, were introduced. The glasses were
prepared in Pt-crucible by melt quenching. The density of the doped glasses takes
the same behaviour of the undoped glasses but a little bit higher because of the
high molecular weight of the RE ions. The structural investigations of binary
magnesium tellurite glasses confirmed the conversion of TeO4 to TeO3 units and
this conversion rate increases faster at MgO ≥ 30 mol%. And at MgO ˃ 45mol%
no glass could be obtained due to the formation of more isolated structural units.
These structural changes suggest that one group of TeO4 connected to 2 groups of
TeO3 structural units needs to stabilize the glass.