Nanocrystalline BaTi2O5 dielectric ceramic prepared by full crystallization from containerless solidified glass

We show that fully dense nanocrystalline titanate ceramic could be obtained by full crystallization from glass which was prepared by a novel contactless solidification process. Through annealing above glass transition temperature T-g for prescribed duration, BaTi2O5 ceramic with grain size of 20-130 nm was successfully fabricated. The dependence of the nanoceramic's dielectric constant and dissipation on frequency was investigated. The results show clearly that the dielectric constant of BaTi2O5 nanoceramic depends on average grain size in nanometer scale, and an optimal range of the grain size is found which exhibits greater dielectric constant than conventional microcrystalline ceramics. The as-fabricated ceramic also possesses lower dielectric dissipation, which can be mainly attributed to the presence of nanometer-sized grains.