Mechanosynthesis of the ferroelectric materials Ba2ANb5O15 (AÂ =Â K, Na, Li)

A novel mechanochemical activation route was applied in order to obtain the Ba2ANb5O15 (A = K, Na, Li) ferroelectric materials. The evolution of the 4BaO2:A2CO3:5Nb2O5 powder mixtures during mechanical treatment and subsequent annealings, was followed by X-ray powder diffraction (XRD), thermal analysis and scanning electron microscopy (SEM). The sought bronze-type phases were mechanosynthesized after 48 h of treatment in a planetary mill. Very crystalline phases can be obtained with very important decreases in the temperatures and reaction times as compared with the traditional ceramic method. Dense ceramics were processed from mechanosynthesized precursors at relative low temperature, by a conventional-sintering route, and their dielectric properties characterized.