An amorphous Bi4Ti3O12 phase was formed when films were grown at <400C

while Bi2Ti2O7 and Bi2Ti4O11 transient phases were developed when films were

grown at 400 to 500 and 600C, respectively. An homogeneous Bi4Ti3O12

crystalline phase was formed in film grown at 700C. The high leakage current

density (5 x 10−7A/cm2 at 0.2MV/cm) of the film grown at 300C under 100mTorr

oxygen partial pressure decreased to 2 x 10−8A/cm2 for film grown at 200mTorr

oxygen partial pressure; due to the decreased number of intrinsic oxygen vacancies.

However, when the oxygen partial pressure exceeded 200mTorr, the electrical

properties were deteriorated due to the formation of oxygen interstitial ions. Mndoping

at a suitable level improved the electrical properties of the films by

producing extrinsic oxygen vacancies that reduced the number of intrinsic oxygen

vacancies. Schottky emission was suggested to be the leakage current mechanism

of the Bi4Ti3O12 film.

Effect of Oxygen Vacancy and Mn-Doping on Electrical Properties of Bi4Ti3O12

Thin Film Grown by Pulsed Laser Deposition. J.Y.Choi, C.H.Choi, K.H.Cho,

T.G.Seong, S.Nahm, C.Y.Kang, S.J.Yoon, J.H.Kim: Acta Materialia, 2009, 57[8],

2454-60