Prakash, B Shri and Varma, KBR (2008) Molten Salt Synthesis of Nanocrystalline Phase of High Dielectric Constant Material $CaCu_{3}Ti_{4}O_{12}$. In: Journal Of Nanoscience And Nanotechnology, 8 (11). pp. 5762-5769.
Full text not available from this repository.Abstract
Nanocrystalline powders of giant dielectric constant material, $CaCu_{3}Ti_{4}O_{12}$(CCTO), have been prepared successfully by the molten salt synthesis (MSS) using KCI at 750 degrees C/10 h, which is significantly lower than the calcination temperature (similar to 1000 degrees C) that is employed to obtain phase pure CCTO in the conventional solid-state reaction route. The water washed molten salt synthesized powder, characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) confirmed to be a phase pure CCTO associated with similar to 150 nm sized crystallites of nearly spherical shape. The decrease in the formation temperature/duration of CCTO in MSS method was attributed to an increase in the diffusion rate or a decrease in the diffusion length of reacting ions in the molten salt medium. As a consequence of liquid phase sintering, pellets of as-synthesized KCI containing CCTO powder exhibited higher sinterability and grain size than that of KCI free CCTO samples prepared by both MSS method and conventional solid-state reaction route. The grain size and the dielectric constant of KCI containing CCTO ceramics increased with increasing sintering temperature (900 degrees C-1050 degrees C). Indeed the dielectric constants of these ceramics were higher than that of KCI free CCTO samples prepared by both MSS method and those obtained via the solid-state reaction route and sintered at the same temperature. Internal barrier layer capacitance (IBLC) model was invoked to correlate the observed dielectric constant with the grain size in these samples.
| Item Type: | Journal Article |
|---|---|
| Additional Information: | Copyright of this article belongs to American Scientific Publishers. |
| Keywords: | Ceramic;Molten Salt Synthesis;Dielectric Properties. |
| Department/Centre: | Division of Chemical Sciences > Materials Research Centre |
| Date Deposited: | 04 Nov 2009 07:04 |
| Last Modified: | 04 Nov 2009 07:04 |
| URI: | http://eprints.iisc.ernet.in/id/eprint/17825 |
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