الفهرس 
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Abstract
The glasses systems 10 xBaTiO3(BT)- xPbTiO3(PT)-60V2O5-30B2O3 with x= 0, 2.5, 5,
7.5 and 10 mol% were prepared by the conventional melt-quenching technique. The raw
material was grinded and melted in electric furnace at 1250° C for 90 min. the glassy
nature of the sample was confirmed using X- ray diffraction (XRD) and differential
scanning calorimetry (DSC). The as-prepared glass samples were heat treated in air at
350 °C for 2 h. 10 % PT sample heat treated at 304 °C for different periods of time:
1,2,4,8 and 24 h to obtain glass ceramic nano-composites. The effects of heat treating
temperatures and times on the structural, electrical and dielectric properties were
investigated by XRD, High resolution transmission electron microscope (HRTEM),
Raman, Dc conductivity and dielectric measurements.
from the XRD studies it is observed that homogenous glasses are formed for BaTiO3
concentration between 0–10 mol %. The heat treated samples show small diffraction
peaks associated with the growth of the crystalline phase in the glassy matrix. DSC
studies show an endothermic dip due to glass transition (Tg) and exothermic peak
corresponding to crystallization (Tc). The glass transition temperature (Tg) increases
with increasing BaTiO3 content showing an increase in bridging oxide (BO). HRTEM
along with SAED images show a small crystalline phase (polar clusters) embedded in
the glass matrix for all glass samples. These clusters grow in size after heat treatment
process. The 10 % PT glass ceramic nano-composite show a growth in the crystalline
phase with the increase in heat treatment time. Raman scattering was used to study the
structure of these glasses and to confirm the existence of an intermediate range order
(polar clusters) in the glassy matrix.