Preparation And Properties Of CCO Ceramics

Most often, the new functional ceramics materials which have high permittivityhave been widely developed in recent years. These materials have potentialapplication values in the field of the electronic industry. It is important in scientificresearch to study the dielectric response mechanism and preparation technology of theceramics materials which have high permittivity. In order to explore new dielectricceramics, the CCO ceramics which have different initial stoichiometric proportionhave been prepared. The relationship among the stoichiometric proportions, crystalstructure and the dielectric property has been investigated. The details of the studycontain two parts as follows:1Ca₂CuO₃ceramics were synthesized by the traditional solid-state sintering methodand colloidal sol gel method. The relationship between the dielectric properties andthe temperature has been researched in the low temperature range. The experimentresults suggested that the dielectric value of the prepared ceramics is about1000inthe frequency102Hz and in the temperature range from120K to240K and thisrelation also implied the relaxation phenomenon. The analysis for the relationshipbetween the permittivity and the temperature has been made by the Arrhenius relation,cole-cole diagrams, Debye relaxation theory. The data-fitting outcome has beenobtained according to the analysis result. The fitting results agree with the experimentdata. In addition, the reason of the dielectric response may come from the hoppingbetween the electronics according to the analysis for the activation energy.2The Ca₂CuO₃-CaCu₂O₃-CuO ceramics were synthesized by traditional solid-statesintering method. The complex dielectric response of the samples measured from10² Hz to10⁶Hz and from300K to500K reveals very high real part of ε＇＞104. Inaddition, the variation of the dielectric constant with different absolute temperaturesuggested the relaxation phenomenon. The comprehensive analysis has been made forthe relationship between dielectric constant and temperature using the Arrheniusrelation, cole-cole diagrams, Schottky barrier model. Analysis results showed that thedielectric response of the prepared ceramics is related to oxygen vacancies and grainboundary barrier.