Giant Anisotropy in La0.7Ca0.3MnO3 Layers Epitaxially on the 71o-BiFeO3 Templates
Ping-fan Chen2*, Yen-lin Huang1, Yin-hao Chu1,2
1Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
2Institute of Physics, Academia Sinica, Taipei, Taiwan
* presenting author:Pingfan Chen,
We selected the BiFeO3 (BFO) with 71o periodic ferroelectric (FE) domains as template to control the EPS in La2/3/Ca1/3MnO3 (LCMO), and this 71o stripe domain structure was along [001]o direction. BFO is one of the rare compounds exhibiting both a large FE polarization and antiferromagnetic order above room temperature, and further these periodic domains can offer additional electric, magnetic and structural perturbation to the above manganite layer. We found that the resistivity difference along the two in-plane orthogonal directions ([001]o and [1-10]o) could be observed in the 40-nm single LCMO films, while no change with the metal-insulator transition temperature (TMI) is induced. Interestingly, when fabricated with the 71o-BFO template, along those two orthogonal directions, not only the difference of resistivity, but also the change of TMI can be obviously obtained in this 40-nm LCMO layer. It shows that the TMI of the LCMO layer in the [1-10]o direction which is vertical to the FE stripe domain can be suppressed by 30 K. Even when we reduced the thickness of LCMO to 25 nm, this LCMO/BFO heterostructure can simultaneously integrate macroscopic metal- and insulator-like transport behavior. We presumed that the anisotropic strain provided by the 71o strip-domain structure would rebuild the pattern of electronic phase separation in LCMO layers, accompanied by the giant anisotropy influenced by the additional various couplings among spin, orbital, charge perturbations.

Keywords: giant anisotropy, multiferroic, La0.67Ca0.33MnO3, BiFeO3, electronic phase separation