CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

imaging, scintillators, lasers, etc. [7-9]. Lanthanide based luminescent materials are prepared
either by complexing Ln 3+ ions with suitable organic ligands or by doping Ln 3+ in an
appropriate inorganic lattices having different dimensions. The reduced optical scattering of
nanometer-sized particles facilitates its use as active materials in polymer or glass based
lasers and amplifiers. Such nanoparticles can be stabilized with suitable ligands during the
synthesis and can be incorporated in different type of matrices. Composites consisting of
luminescent nanoparticles dispersed in a polymer matrix are interesting materials. Such
materials have certain advantages as the polymer lattice offers good processability and
desirable mechanical properties while the inorganic luminescent material provides high
luminescence efficiency and long-term chemical stability.
During the present investigation, a variety of inorganic matrices varying from oxides
(Ga 2 O 3 , Sb 2 O 3 ), phosphates (SbPO 4 , BiPO 4 , GaPO 4 ), gallate (ZnGa 2 O 4 ) to tungstates
(CaWO 4 , SrWO 4 , BaWO 4 ) have been doped by lanthanide ions. Choice of the materials has
been made by considering the environment around the cation which would be substituted by
incoming lanthanide ion, phonon energy of the lattice and luminescent character of the host.
Some of the materials have been incorporated into sol-gel and polymer films with a view to
make luminescent films for different applications. The thesis is divided into 7 chapters each
of which is briefly discussed below.
General and basic aspects of nanomaterials are discussed in Chapter 1. It contains
brief introduction about the history of nanomaterials, different types of nanomaterials, their
properties and applications. Emphasis is given to luminescent properties of different types of
nanomaterials. Various methods used for the synthesis of nanomaterials are discussed briefly.
As the present study mainly deals with the lanthanide ions doped nanomaterials, an overview
of lanthanide ions luminescence in solids and its dependence on concentration in the host,
particle size of the host, etc. has been given.
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