Effect of temperature on grain size, phase composition, and electrical properties in the relaxor-ferroelectric-system Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 -: art. no. 024102

Relaxor ferroelectrics near the morphotropic phase boundary were prepared by pressureless sintering at various temperatures in order to study the influence of grain size on phase composition and electrical properties. Investigations of the microstructure indicate an increase in grain size from 0.5 to 3.7 mu m when the sintering temperature is increased from 1050 to 1290 degrees C. The corresponding phase composition is changed from predominantly rhombohedral for small grain sizes to more than 80% tetragonal for larger grain sizes. Low-voltage measurements of poled and unpoled samples correlate well with the x-ray diffraction results. An increase of the permittivity after poling is found for samples with a high tetragonal phase content, while samples with a predominantly rhombohedral composition show a slight decrease. The remanent polarization as well as uni- and bipolar strain increase with increasing sintering temperature by a factor larger than 2, whereas the coercive field E-C remains nearly constant for all sintering conditions. (c) 2005 American Institute of Physics.