Role of Mn in controlling the dielectric loss and ageing effect in Pb(Zn1/3Nb2/3)O3–Pb(Fe2/3W1/3)O3–Pb(Fe1/2Nb1/2)O3

Compositions in the Pb(Zn1/3Nb2/3)O3–Pb(Fe2/3W1/3)O3–Pb(Fe1/2Nb1/2)O3 (PZN–PFW–PFN) system show a high dielectric constant, insulation resistance and bend strength. In addition they can be sintered at very low temperatures. Hence they find technological applications as multilayer capacitors with low cost Ag-based internal electrodes. The dielectric loss in these ceramics was controlled by doping with Mn in the form of Mn-acetate, MnO2, and Pb(Mn1/3Nb2/3)O3. The subtle differences in the dielectric properties of PZN–PFW–PFN, when Mn is taken in these forms are reported in this paper. A possible way of controlling the ageing effect is highlighted. © 1998 Chapman & Hall