Effect of Dy doping on resistance degradation of (Ba) (Ti, Zr) O3 sintered in reducing atmosphere under highly accelerated life test

Substitution of Dy rare earth ions in Ba (Ti, Zr) O-3 dielectric materials was studied, using X-ray diffraction. Dy3+ ions enter both the A- and B-sites of the perovskite structure, depending on whether there is a Ba or Ti-excess. There are two discrete mechanisms of occupancy: 1) all Dy ions enter only Ti-sites as acceptors when Dy concentration is below 2 mol%; 2) Dy3+ enters Ba- and Ti-sites when Dy concentration is above 2 mol%. The DyBa1+ donor is highly effective in improving the life stability by 10 orders of magnitude. Besides, oxygen vacancies being compensated by the existence of Dy-Ba(1+) which acts as a donor, impedance measurements indicated the existence of an insulating barrier layer, which could help to suppress electromigration of oxygen vacancies, thus the life stability at grain boundaries can be improved by Dy3+ incorporation into Ba-site-donors.