Single domain multiferroic BiFeO3 films
J. C. Yang1, C. Y. Kuo1, C. K. Wang2*, Z. Hu1, H. J. Liu2, Y. H. Chu2
1Max-Planck Institute for Chemical Physics of Solids, Dreden, Germany
2Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
* presenting author:Chih-Kuo Wang,
Multiferroic BiFeO3 has antiferromagnetism coupled strongly with ferroelectricity above room temperature, thereby sheds the light on additional degrees of freedom to trigger new functionalities. However, the application potential could be limited if BiFeO3 film has multi domain, which complicates the understanding and interpreting of the fundamental properties as well as suppress the both net magnetic and ferroelectric contribution. Here, we report the realization of the three single well defined parameters of BiFeO3 film, i.e. a single anti-ferromagnetic axis parallel to b-axis, a ferromagnetic momentum induced by Dzyaloshinskii-Moriya interaction parallel to a-axis and a ferroelectric polarization parallel to c-axis. To strength the ferromagnetic functionality in such single domain BiFeO3 thin film, we study the exchange interaction across Co/BiFeO3 heterostructure. The result reveals that the ferromagnetic moment of Co metal can couple directly to ferromagnetic momentum induced in BiFeO3. The realization of the single domain BiFeO3 films thus opens a new door towards advanced functional materials as well as new nanoelectronics.

Keywords: multiferroic , BiFeO3, thin film , pulsed laser deposition, complex oxide