Ceramics-Silikáty 27, (2) 97 - 105 (1983)

X -ray structural analysis and X-ray spectral microanalysis have proved a heterogeneous phase structure of piezoceramics based on MnO₂ doped solid solutions Pb(Mg_1/3Nb_2/3)TiZrO₃. According to the sintering conditions, the ceramics contains, beside the perovskite phase, also the pyrochloric phase (Pb₂Nb₂O₇) and phases in which the Mg, Mn and Ti elements are concentrated. A lower PbO content in sintered samples leads to a greater inhomogeneity of compostition, but also to a higher density of the sintered specimens. Relation­ ships are pointed out between the mutual distribution of the perovskite and pyrochloric phases, apparent density and temperature and time stability of the properties of the system in question.