Diffuse phase transition in (Na,Bi)-doped PbSnxTi1-xO3 ferroelectric ceramics

The temperature dependence of the dielectric behavior of Pb-0.85(Na0.5Bi0.5 )(0.15)SnxTi1-xO3 (PSNB) with x = 0.40, 0.45, 0.50, 0.55, 0.60 has been inv estigated, A careful analysis of the dielectric properties reveals a relaxe r behavior near T-c where the diffuseness parameter (delta) increases as th e content of Sn4+. It is observed that the temperature of the permittivity maximum shifts toward lower temperatures and the permittivity maximum decre ases with the increase of Sn content in the PSNB solid solutions. The diffu seness (delta) and deformation structure (gamma) parameters were determined for each composition using the results of the dielectric measurements and experimental lattice constant values. (C) 1999 Elsevier Science Ltd. All ri ghts reserved.