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Title: A study on the thermal behaviour of some polycrystalline inorganic complexes by xray diffraction and physical methods
Researcher: Bora, Mohendra Nath
Guide(s): Mahanta, P C
Keywords: Anisotropic
University: Gauhati University
Completed Date: 31/12/1973
Abstract: Detailed studies on thermal behaviours of kaolinite, illite and of intersalated kaolinite complexes with the acetates of potassium and caesium have been made by different methods such as X-ray diffraction, Dielectric measurements, Differential Thermal Analysis and Infra-red spectroscopy. Measurements of the thermal expansion along [001] of the samples have been made by X-ray diffraction over the temperature range 77K to 875K for kaolinite and its intersalated complexes with the acetates of potassium and caesium, and over the range 77K to 1375K for illite. Measurements of the dielectric properties along [001] and also the anisotropic behaviour along the direction of the preferred orientation have been made. Intersalation of the acetates of potassium and caesium into the sheets of kaolinite is found to be a low tempe-rature phenomenon. During intersalation, the acetate ions trapped between layers of potassium-water solution, directly enters into the interlayer space of kaolinite structure, resulting thereby the lattice expansion to about 14.1A. A structural model for the intersalation have been proposed. Anomalous behaviour of thermal expansions, rapid rise of capacitances and conductances, decrease in the absorption peaks assigned to OH- Stretching Vibrations, and increase in the rate of reactions as indicated by the shift of peak temperatures in the thermograms are attributed to the formation of lattice defects in the clay samples due to dehydroylation, and in the complexes, due to intersalation of kaolinite with the acetates. The studies on sodium doped kaolinite agree more or less with the idea of creation of the complex color centers and their influence in the dielectric properties. The values of activation energies for various processes activated at different temperatures have been determined.
Appears in Departments:Department of Physics

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01_title page.pdfAttached File14.76 kBAdobe PDFView/Open
02_acknowledgement.pdf23.62 kBAdobe PDFView/Open
03_abstract.pdf38.71 kBAdobe PDFView/Open
04_content.pdf127 kBAdobe PDFView/Open
05_chapter 1.pdf301.03 kBAdobe PDFView/Open
06_chapter 2.pdf202.35 kBAdobe PDFView/Open
07_chapter 3.pdf1.77 MBAdobe PDFView/Open
08_results and discussion.pdf1.99 MBAdobe PDFView/Open
09_general discussion.pdf502.84 kBAdobe PDFView/Open
10_conclusion.pdf22.31 kBAdobe PDFView/Open
11_appendix.pdf1.24 MBAdobe PDFView/Open
12_references.pdf125.68 kBAdobe PDFView/Open

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