Substituent-introduction of "hard" polarization characteristics in "soft" Pb(BIBII)O-3-PbTiO3 ferroelectric ceramics

The polarization versus field (P-E) characteristics of modified Pb(Mg1/3Nb2 /3)O-3-PbTiO3 (PMN-PT) and Pb(Sc1/2Nb1/2)O-3-PbTiO3 (PSN-PT) ceramics has b een investigated for compositions close to the morphotropic phase boundary. Investigations were performed for various types of lower valent substituen ts on the B-site cation positions. It has been found possible to introduce "hard" P-E characteristics in "soft" PMN-PT and PSN-PT ferroelectric cerami cs. In PMN-PT, only Mn was found to be effective in introducing such charac teristics, however, in PSN-PT various lower valent substituents on higher v alent sites were found to be effective. The results indicate that using a d efect-engineering approach that it may be possible to develop materials wit h combinatory characteristics of hard and soft ferroelectrics. (C) 2001 Ame rican Institute of Physics.