A positron lifetime study of lanthanum and niobium doped Pb(Zr0.6Ti0.4)O3

A study of vacancy-related defects in lanthanum and niobium doped
PbZr0.6Ti0.4O3 with dopant concentrations of 0-6 and 0-4 mol%,
respectively has been performed using positron annihilation
spectroscopy X-ray diffraction, and photoelectron spectroscopy.
Positron lifetime as well as coincidence annihilation radiation Doppler
line broadening measurements were carried out. It was found that the
samples exhibit vacancylike defects that act as positron traps. Two
main defect lifetime components were found in both sample sets one at
approximate to150 ps and one at approximate to300 ps. These defect
trapping sites can be attributed to single oxygen vacancies and A-site
vacancies, respectively. Doppler line broadening measurements, however,
do not show significant changes as a function of dopant concentrations
in terms of shape S and wing W parameters.