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Title: Structural dielectric and spectroscopic investigations of sol gel derived titania poly vinyl pyrrolidine hybrids
Researcher: Vasudevan, Prathibha
Guide(s): Unnikrishnan, N V
Keywords: Colorimetry
Hybrid materials
Impedance microscopy
Poly vinyl pyrrolidine
Sol gel process
Titanium dioxide
Transmission electron microscopy
Upload Date: 23-Jun-2014
University: Mahatma Gandhi University
Completed Date: 27/09/2012
Abstract: The development of novel materials and the assessment of their potential applications constitute a major fraction of today s scientific research efforts. Among all the research fields in material science, inorganic-organic hybrids are the most rapidly growing one. Furthermore, it is estimated that nanotechnology has grown into a multibillion dollar industry and may become the most dominant single technology of the twenty-first century. This study focuses on the structural, dielectric and spectroscopic investigations of sol-gel derived Titania/Poly (vinyl-pyrrolidone) hybrids. Various techniques like FTIR spectroscopy, TGA/DTA, XRD, TEM, AFM, SEM, dielectric spectroscopy, UV-VIS spectroscopy and fluorescence spectroscopy were used to assess the structural and optical properties of these hybrid materials. The spectroscopic investigations of the rare earth doped hybrid materials, mainly europium ions and samarium ions are described in respect of their qualitative and quantitative aspects. TiO2/PVP nanocomposites with varying TiO2 concentrations were also characterized for their dielectric response nature. It shows low dielectric constant and dielectric loss with high frequency suggesting an enhanced optical quality for the samples with lesser defects. The conductivity curve shows an increasing tendency with increase in frequency and found to obey Jonscher s power law. Co-doped rare earth cations Tb3+ and Eu3+ aggregated as luminescent centers within the hybrid matrix, in a controlled manner resulted in the white-light phosphors with tunable emission properties. An efficient energy transfer occurs from Tb3+ to Eu3+, due to the energy overlap between Tb3+ and Eu3+ in the hybrid matrix. RGB emission is also observed from the hybrid matrix codoped with rare earth ions (Tb3+ and Eu3+) newline
Pagination: xxvii, 162p. iv
Appears in Departments:School of Pure and Applied Physics

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01_title.pdfAttached File155.91 kBAdobe PDFView/Open
02_declaration.pdf72.39 kBAdobe PDFView/Open
03_certificate.pdf286.58 kBAdobe PDFView/Open
04_acknowledgement.pdf92.73 kBAdobe PDFView/Open
05_contents.pdf91.53 kBAdobe PDFView/Open
06_list_of_tables.pdf65.65 kBAdobe PDFView/Open
07_list_of_figures.pdf96.26 kBAdobe PDFView/Open
08_abstract.pdf85.03 kBAdobe PDFView/Open
09_preface.pdf104.53 kBAdobe PDFView/Open
10_list_of_publications.pdf111.72 kBAdobe PDFView/Open
11_chapter1.pdf406.94 kBAdobe PDFView/Open
12_chapter2.pdf2.24 MBAdobe PDFView/Open
13_chapter3.pdf1.28 MBAdobe PDFView/Open
14_chapter4.pdf290.1 kBAdobe PDFView/Open
15_chapter5.pdf833.78 kBAdobe PDFView/Open
16_appendix.pdf19.31 kBAdobe PDFView/Open

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