Ferroelectric Pb(Zr60Ti40)O-3 ceramics sintered for 6 hours at 1050
degreesC in air and doped with La or Nb in the range 0.5 to 6 mol% have
been investigated by positron lifetime spectroscopy and two-dimensional
coincident Doppler measurements. The undoped samples show two lifetime
components with a defect lifetime of about 250 ps. After doping this
defect lifetime increases to about 295 ps. The influence of the doping
on the Doppler spectra is extremely small. Additional XRD pattern show
a significant correlation between doping and lattice structure.