Published online by Cambridge University Press: 31 January 2011
The electron irradiation sensitivities of Pb(Mg1/3Nb2/3)O3 (PMN) and Pb1−xLax[Mg(1+x)/3Nb(2−x)/3]O3 (PLMN) ceramics were investigated by transmission electron microscopy. Nanoscale Pb particles formed in these materials under electron beam radiation. It was found that these fine Pb particles generally had a preferred crystallographic orientation relationship with the PMN/PLMN host and always existed at positions slightly rich in Mg2+. A preliminary mechanism involving defect chemistry reactions is proposed to interpret this unusual Pb precipitation. Possible limitations to the practical applications of these materials are discussed.