Mechanism of leakage current reduction by adding WO3 to crystallized TA(2)O(5)

The addition Of WO3 to Ta2O5 suppresses the formation of oxygen vacancies d uring crystallization and reduces the leakage current of crystallized Ta2O5 . By adding 3.8 at% WO3 to crystallized Ta2O5, a leak-age current reduction of four orders of magnitude was achieved. This leakage current reduction i s due to the replacement of Ta5+ ions by smaller W6+ ions, which relaxes th e stress induced by extension and distortion along the c-axis on crystalliz ation and thereby suppresses the formation of oxygen vacancies in beta -Ta2 O5.