Room temperature magnetic field modulation of diode-like behavior in Ca-doped BiFeO3 thin films.

Bi_1-xCa_xFeO₃ (x = 0, 0.1) thin films were synthesized by a sol-gel spin coating method. A diode-like current–voltage characteristic was investigated in a Bi_0.9Ca_0.1FeO₃ (BCFO) thin film. By Ca element doping, the current–voltage characteristic was changed from a traditional symmetric variation to a diode-like behavior. Besides, the modulation effects of a magnetic field on Pt/BCFO/Pt/Ti/SiO₂/Si devices have been investigated. Using some micro-analysis methods, such as x-ray photoelectron spectroscopy and transmission electron microscopy, possible mechanisms were discussed on the basis of an oxygen vacancy modulated Schottky-like barrier. The control of the resistance state with the magnetic field means larger degrees of freedom, and this is crucial for further application of BiFeO₃-based materials in higher density memory devices. [ABSTRACT FROM AUTHOR]