Phase transition and physical features of nano-grained BaTiO3 ceramics Prepared by two-step sintering.

Nano-grained BaTiO3 ceramics were prepared by two-step sintering; nanoscale BaTiO3 powders of 100 and 500 nm in size were used as starting materials. The phase transition and physical features of the BaTiO3 ceramics were investigated as a function of the grain size and the boundary decoration. With increasing the grain size, the relative volume fraction of a tetragonal phase was increased; this seems to be due to the variation in boundary tension with grain size. The relation of the physical features of the nano-grained BaTiO3 ceramics with the structural variation is discussed in terms of process parameters.