Electrical conductivity in lead titanate zirconate ceramics

Abstract Ferroelectric lead titanate zirconate ceramics prepared by sintering in air are found to have p -type conductivity, believed to result from an excess of lead vacancies. Donor substituants for lead, titanium, or zirconium reduce the conductivity by electron-hole compensation, but n -type conductivity is not observed and is probably prevented by the formation of lead site vacancies. The data supporting this view are presented. These include observations on the effect of donor and acceptor doping and of oxygen pressure during sintering on resistivity, and measurements of thermal e.m.f. A comparison is made between effects observed in lead titanate zirconate ceramics and those in barium titanate, which can have high n -type conductivity at room temperature after doping, and in barium zirconate.