Reversible permittivity of multicomponent PMN-PT-based ceramics

The reversible permittivity of Ba-doped ceramics of the multicomponent system $m$PbMg$_{1/3}$Nb$_{2/3}$O$_3$–$n$PbNi$_{1/3}$Nb$_{2/3}$O$_3$–$y$PbZn$_{1/3}$Nb$_{2/3}$O$_3$–$x$PbTiO$_3$ ($m$ = 0.1298 – 0.4844, $n$ = 0.1266 – 0.4326, $y$ = 0.0842 – 0.130, $x$ = 0.25–0.40) is studied. The reversible permittivities of cubic, heterophase, and tetragonal ceramics are analyzed under various experimental conditions, such as the measuring ac electric field frequency and the time of residence in a dc bias electric field. The transformation of permittivity minima into a plateau and the subsequent disappearance of all anomalies as the lead titanate concentration decreases are assumed to be related to a change in the initial domain structure of the material. A diagram illustrating the dependence of the tunability coefficient on the lead titanate concentration is plotted, and the ceramic compositions that correspond to the characteristic dependences of reversible permittivity are determined.