Electrical behavior and oxygen vacancies in BiFeO3/[(Bi 1/2Na1/2)0.94Ba0.06] TiO3 thin film

Abstract

Multiferroic bilayered thin films consisting of BiFeO3/[(Bi 1/2Na1/2)0.94Ba0.06] TiO3 (BNBT) and BiFeO3 (BFO) nanolayers were successfully grown on Pt/ TiO2/SiO2/Si substrates via a combined sol-gel and radio frequency sputtering route. The bilayered BFO/BNBT thin film with (110) orientation and dense texture exhibits excellent ferroelectric and dielectric behavior (e.g., 2 Pr ∼79.7 μC/ cm2, 2 Ec ∼772.6 kV/cm, εr ∼178, and tan δ∼0.03), together with a long fatigue endurance up to 1× 1010 switching cycles, while the desired magnetic behavior is well retained. Impedance study suggested that the second ionization of oxygen vacancies was involved in the conduction of the bilayered BFO/BNBT thin film. © 2009 American Institute of Physics.