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The morphotrophic phase boundary compositions of Ba doped Pb 1−3x/2 La x x (Zr y T i 1−y )O 3 (1.2/55/45) ceramics are synthesized for x = 0 to 6 mole% by mixedoxide method and characterized for phase formation, microstructure, dielectric and relaxor studies. Density of ceramics is increased as Ba concentration is increased. Coexistence of rhombohedral and tetragonal phases is strong in 5 mole % Ba doped PLZT composition near morphotrophic phase boundary of PLZT phase diagram. Scanning electron micrographs indicate the grain size control as Ba concentration increases in PLZT system. ε rt and Tanδ are increased up to 4 mole% Ba doped PLZT system. Dielectric maximum (ε T c ) is decreased to 4 mole% Ba and increased to 6 mole% Ba. Curie temperature (T c ) decreased substantially with increase of Ba concentration in PLZT system. Relaxor behavior of the system is characterized over range of 200 kHz.

The solid solutions of La modified xPb(Mg 1/3 Nb 2/3 )-(1−x)Pb(Zr 0.55 Ti 0.45 )O 3 ceramic system are synthesized by columbite precursor method and characterized for phase formation, microstructure, dielectric and relaxor studies. Powder X-ray diffraction patterns indicate pseudocubic phase of compositions on PMN-PZT system phase diagram. La doping in PMN-PZT system inhibited grain growth while increasing grain size with PMN concentration. Density of the ceramics is increased to 1.5 mole% La doped PMN-PZT compositions and decreased with the increment of PMN concentration. ε RT and Tanδ are increased to 1.5 mole% La doped PMN-PZT compositions while ε T c and T c are decreased with La modification in PMN-PZT system. Pure and La modified 0.8PMN-0.2PZT compositions have shown the most promising relaxor behavior applicable to multilayer capacitor (MLC) applications.