Surface modification of Dy2O3–Nb2O5 dope mix for dielectric materials in aqueous dispersion

The electrokinetic mismatch between the basic dielectric compound (Ba,Ca)(Ti,Zr)O3 (BCTZ) and Dy2O3–Nb2O5 dope mix in aqueous suspensions has been improved by a pre-firing and milling treatment of the dope mix. Pre-fired dope mix showed a much higher zeta potential which resulted in a drastic improvement of the particle dispersion in aqueous slurries. By use of surface-modified dope mix the homogeneity of the micro structure of multilayer ceramic capacitors is improved and the break-down voltage of thin (7 μm) dielectric layers increased. The results observed indicate the critical influence of the micro structural homogeneity on the breakdown voltage of MLCCs.