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dc.contributor.advisorVarma, K B R
dc.contributor.authorShri Prakash, B
dc.date.accessioned2010-05-24T11:01:14Z
dc.date.accessioned2018-07-30T15:08:33Z
dc.date.available2010-05-24T11:01:14Z
dc.date.available2018-07-30T15:08:33Z
dc.date.issued2010-05-24
dc.date.submitted2007-10
dc.identifier.urihttp://etd.iisc.ac.in/handle/2005/688
dc.description.abstractHigh dielectric constant materials are of technological importance as they lead to the miniaturization of the electronic devices. In this context, the observation of anomalously high dielectric constant (>104) in the body-centered cubic perovskite-related (Space group Im3) material Calcium Copper Titanate ((CaCu3Ti4O12)(CCTO)) over wide frequency (100 Hz – 1MHz at RT) and temperature (100 – 600 K at 1 kHz ) ranges has attracted a great deal of attention. However, high dielectric constant in CCTO is not well understood yet, though internal barrier layer capacitor (IBLC) mechanism is widely been accepted. Therefore, the present work has been focused on the preparation and characterization of CCTO ceramic and to have an insight into the origin of high dielectric constant. Influence of calcination temperature, processing conditions, microstructure (and hence grain size), composition, doping etc on the electrical characteristics of CCTO ceramics were investigated. Electrical properties were found to be strongly dependent on these parameters. The dielectric constant in CCTO was observed to be reduced considerably on substituting La+3 on Ca+2 site. The formation temperature of CCTO was lowered substantially (when compared to conventional solid-state reaction route) by adopting molten-salt synthesis. The dielectric loss in CCTO was reduced by incorporating glassy phases at the grain boundary. Potential candidates for the practical applications such as charge storage devices, capacitors etc, with dielectric constant as high as 700 at 300 K was accomplished in a three-phase percolative composite fabricated by incorporating Aluminium particle into CCTO-epoxy composite. Polycrystalline CCTO thin films with dielectric constant as high as ~ 5000 (1 kHz and 400 K) were fabricated on Pt(111)/Ti/SiO2/Si substrates using radio frequency magnetron sputtering. Effect of sintering conditions on the microstructural, ferroelectric and varistor properties of CCTO and LCTO ceramics belonging to the high and low dielectric constant members of ACu3M4O12 family of oxides were investigated in detail and are compared. Ferroelectric-like hysteresis loop (P vs E) and weak pyroelectricity were observed in CCTO and plausible mechanisms for this unusual phenomenon have been proposed.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseriesG22151en_US
dc.subjectCalcium Titanateen_US
dc.subjectDielectric Materialen_US
dc.subjectFerroelectric Materialsen_US
dc.subjectCalcium Copper Titanate Ceramics - Dielectric Propertiesen_US
dc.subjectCalcium Copper Titanateen_US
dc.subjectHigh Dielectric Constant Materialsen_US
dc.subjectCaCu3Ti4O12 Ceramicsen_US
dc.subject.classificationMaterials Scienceen_US
dc.titleInvestigations Into The Microstructure-Property Correlation In Doped And Undoped Giant Dielectric Constant Material CaCu3Ti4O12en_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.disciplineFaculty of Scienceen_US


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