Dependence of breakdown field on dielectric (interelectrode) thickness in base-metal electroded multilayer capacitors

The authors have empirically determined the dependence of breakdown field EB versus dielectric thickness d (electrode separation) for a large number (4100) of BaTiO3-based multilayer capacitors with Ni base-metal electrodes. The data averaged over lateral area show for 6<d<22μm that EB=const×d−n, where n=0.50±0.06, a result compatible with macroscopic “thermal” dc breakdown mechanisms. More precisely, however, the results nearly perfectly fit a situation of breakdown occurring in connected defects from collision ionization resulting from field emission from the cathode.