الفهرس 
CHAPTER ? THEORITICAL BACKGROUNDOnly 14 pages are availabe for public view
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Abstract
The present thesis consists of three chapters and ended with Arabic and English summaries, a list of references is also given. The present work includes joint experimental and theoretical parts. Experimentally, we have prepared novel composite systems of CdS nanoparticles embedded in borophosphate glass system (CaO-K2ONa2O-
B2O3-P2O5). The prepared systems were characterized by differential thermal analysis (DTA), differential scanning calorimetry (DSC), X-ray diffraction (XRD),density measurements and determination of molar volume, transmittance electron microscopy (TEM), optical absorption (UV-Vis), infrared (IR), and Raman spectroscopy. Different nanoparticles sizes were prepared by changing the annealing conditions like temperature and time.Theoretically, General background on quantum chemical calculations in addition to an overview of the density functional theory (DFT) has been given a detail description of the procedures used throughout this work. We used a rapid energy
optimization method, such as a semiemprical (PM3) or an SCF with an STO-3G basis
set. from the minima obtained in this way, we started a full energy optimization using
DFT at B3LYP/3-21G (d) level. Geometry optimizations for different borophosphate
glass models under investigation have been conducted at B3LYP/ LanL2DZ level using
the Gaussian 03 suite of programs.
Chapter (I): Introduction
This chapter includes a scientific literature survey related to:
i) Nanocrystals, nanotechnology, nanomaterials, history of nanomaterials,
classification of nanostructured materials and their coordination
compounds regarding their types, design and synthesis, their chemical,
physical, electronics and biochemical importance.
ii) The fundamental issues in nanomaterials.
iii) Semiconductor quantum dots, general properties of semiconductor
quantum dots, quantum size effect in metal or semiconductor
nanoparticles, exciton in semiconductor quantum dots, quantum
English summary
confinement, dimensionality, quantum confinement regimes and crystal
structure of II-VI semiconductor materials.
iv) Nanocrystals in glass matrices, the nature of glassy state, classification of
glasses, structure of phosphate glasses, borophosphate glasses,
fabrication of quantum dots in glass and growth of nanocrystals in glass
matrices.
v) Theoretical models and effective -mass approximation.
vi) Experimentally and theoretically literature review on semiconductor
nanocrystals in glasses.
Chapter (II): Materials and Methods
This chapter includes two main parts:
i) Experimental Section
This part includes a detailed account about the method of preparing the undoped
borophosphate glasses and doped borophosphate glasses with semiconductor CdS
nanocrystals [8 % CaO-5 % K2O- x Na2O-15 % B2O3-(72%-x) P2O5], where x = 17, 10
and 7 mole % doped with 1-3 wt % (CdO + S) content. Reliable characterization
methods are critical in developing efficient nanoparticles composites. Various structural
parameters, such as nanoparticles size, nanoparticles size distribution, specific surface
area, and encapsulated nanoparticles, are some of the important features that need to be
evaluated. The techniques used to characterize the samples include, differential thermal
analysis (DTA), differential scanning calorimetry (DSC), X-ray diffraction (XRD),
density measurements and determination of molar volume, transmittance electron
microscopy (TEM), optical absorption (UV-Vis), infrared (IR), and Raman
spectroscopy.
ii) Computational details Section
This part presents general background on quantum chemical calculations in
addition to an overview of the density functional theory has been given a detail
description of the procedures used throughout this work. Geometry optimizations for
different borophosphate glass models have been conducted using density functional
theory at the B3LYP/ LanL2DZ level of theory.