Lead zirconate titanate ceramics with certain 3‐ or 5‐valent additions (lanthanum, neodynium, tantalum, and niobium) are found to be characterized by low aging of electrical and mechanical properties, a well‐defined hysteresis loop, and by high electrical and mechanical losses. Experimental investigations are reported on plain lead zirconate titanate and on a low‐aging niobium modification.The experiments included an electron microscope study of the ceramics and a number of electrical measurements. As a result of the study, the changed properties of the substituted material have been explained as being due to domain wall motion under low electric field. The results of electrical measurements supporting this conclusion, and a hypothesis accounting for the effects in terms of lattice vacancies, are presented.The 3‐ or 5‐valent additives described in the foregoing also cause greatly increased volume resistivity in the ceramic. This has not been satisfactorily explained.