ON THE PEROVSKITE-RELATED MATERIALS OF HIGH DIELECTRIC PERMITTIVITY WITH SMALL TEMPERATURE-DEPENDENCE AND LOW DIELECTRIC LOSS

Dielectric properties of quantum paraelectric materials, SrTiO3, CaTiO 3 and (La1/2Na1/2)TiO3, were presented and discussed since they show t he titled dielectric properties in the lowest temperature range. In or der to show our strategy to obtain the titled materials for microwave resonator applications, dielectric properties of several solid solutio n systems, SrTiO3-LaAlO3, Sr2TiO4-SrLaAlO4 and BaTiO3-Ba(Mg1/3Ta1/3)O- 3 were exemplified. Concerning about relaxer ferroelectric materials, it is pointed out that a drastic broadening of ferroelectric phase tra nsitions in the KNbO3-BaTiO3 and BaTiO3-Ba(Fe1/2Ta1/2)O-3 solid soluti on systems is caused by a strong local field fractuation come from the randomly oriented permanent electric dipoles produced by the heteroge neous cationic charge distribution in the solid solution.