Q. Tan et al., Commonalties of the influence of lower valent A-site and B-site modifications on lead zirconate titanate ferroelectrics and antiferroelectrics, J MATER RES, 14(2), 1999, pp. 465-475
Studies of the structure-property relations of lead zirconate titanate (PZT
) modified with lower valent substitutions on the A- and B-sites have been
performed as a function of substituent concentration. These investigations
have yielded common changes induced by these substitutions on ferroelectric
phases. The commonalties are the presence of fine domains and polarization
pinning effects. Differences in domain morphologies were observed between
the rhombohedral and tetragonal ferroelectric phases. Rhombohedral ferroele
ctrics were found to exhibit "wavy" domain patterns with increasing dopant
concentrations, whereas a lenticular domain shape was preserved as the doma
in size was decreased for tetragonal ferroelectrics. These differences were
explained in terms of different pinning mechanisms based on the difference
s in local elastic strain accommodations. Investigations of high Zr-content
PZT have revealed that the ferroelectric rhombohedral phase becomes stabil
ized over the antiferroelectric orthorhombic with increasing concentrations
of lower valent modifications. This change was explained in terms of the e
nhanced coupling between oxygen octahedra due to the bonding of oxygen-vaca
ncy dipoles.