| Abstract: | The effects of Ca2+ ions on the structure and dielectric and pyroelectric characteristics of PbTiO3 polycrystals were investigated. With increasing content of Ca, a decrease in tetragonal axial ratio (c/a) was observed as a consequence of shrinkage of the lattice parameter c. The dielectric constant and pyroelectric coefficient increase and Curie temperature (TC) shifts toward lower temperature with increasing content of Ca. The theory of ferroelectric soft mode has been developed to illuminate the relationship between the structure and properties of the polycrystal. |
