Aging studies of some Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/-(Ba,Sr)TiO/sub 3/ ceramics

Relaxor ferroelectrics, such as PMN, have a nonconventional domain structure compared to a normal ferroelectric; and thus have aging characteristics that manifest themselves in a somewhat different manner. The focus of this research is to study the effects of aging on PMN based compositions. The samples tested include a number of compositions in the Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/PbTiO/sub 3/-(Ba,Sr)TiO/sub 3/ ternary. The samples were originally fabricated using a columbite precursor mixed oxide method. The electromechanical properties (strain and hysteresis), polarization and weak field permittivity were measured as a function of frequency and temperature for samples aged around ten years. The characteristic "saddle" in the dielectric temperature curves has been investigated for its dependence on time, temperature and frequency. A spectral analysis of these responses shows that the aging effects are apparent in the higher harmonics of the material.