摘要

Aging of Na0.5 + xBi0.5 - xTiO3 - x (x = 0, 0.02) ceramics is studied by dielectric measurements. The time dependence of the dielectric property is well fitted by the stretched exponential function. The observed aging temperature dependences are different between Na0.52Bi0.48TiO2.98 and Na0.5Bi0.5TiO3 in relation with the concentration of oxygen vacancies. The aging temperature dependences of the relaxation intensity and the relaxation time in Na0.52Bi0.48TiO2.98 (which contains more oxygen vacancies) is consistent with the result of Monte-Carlo simulation which is based on the relaxation of defect dipoles in relaxor ferroelectrics. It is found that the oxygen vacancies are mainly responsible for the defect dipole. The aging behavior can be explained on the basis of the size of defect-dipole and its distribution.

  • 出版日期2008