Tuning The Magnetic Properties of BiFeO3-CoFe2O4 Nanocomposite via Magnetostructural Transition of BiFeO3 Matrix
Tahta Amrillah1*, Suresh Kumar2, Sheng-Chieh Liao3, Chih-Ya Tsai4, Yi-Ying Chin5, Yen-Ting Liu5, Man-Ling Lin1, Yugandar Bitla2, Qing He6, Hsin-Yi Lee5, Chih-Huang Lai3, Ying-Hao Chu2, Jenh-Yih Juang1
1Electrophysics, NCTU, Hsinchu 30010, Taiwan
2Material Science and Enginering, NCTU, Hsinchu 30010, Taiwan
3Material Science and Enginering, NTHU, Hsinchu 30013, Taiwan
4Photonics and Institute of Electro-Optical Enginering, NCTU, Hsinchu 30010, Taiwan
5National Synchroton Radiation Research Center, Hsinchu 30076, Taiwan
6Physics, Durham University, Durham DH1 3LE, UK
* presenting author:tahta amrillah, email:tahvisikawan@gmail.com
Multiferroic materials in the form of nano-composite thin films with two distinct phases has been topic of intense research for their profound applications in the field of spintronics. Besides growing high quality, phase separate nanostructured thin films, the strain engineering that is conduce to enhance the ferroelectric properties and the magnetic anisotropy of the ferromagnetic phase and magnetoelectric coupling between the phases have to be given utmost importance in exploring the new possibilities.
We investigate the magnetostructural coupling between anti-ferromagnetic BiFeO3 (BFO) and ferrimagnetic CoFe2O4 (CFO) in BFO-CFO self-assembled, vertically aligned nanocomposites (VAN) grown on LAO and STO substrate. It has been well established that BFO has tetragonal (T) and rhombohedral (R) as stable phases and CFO has high magnetocrystalline anisotropy, even in the form of nanostructures. The temperature and magnetic field dependent magnetization of T_BFO-CFO/LAO and R_BFO-CFO/STO nanostructures primarily demonstrates the interplay among these variants. CFO with R_BFO exhibits larger magnetic anisotropy and higher magnetic transition temperature compared to that of T_BFO. Detailed analysis of the anisotropic exchange energy between the FM-AFM interfaces in T_BFO–CFO/LAO and R_BFO-CFO/STO will be presented and discussed in the light of dual role played by BFO in its two different structural phases.

Keywords: BiFeO3, CoFe2O4, Magnetostructural, Tetragonal, Rhombohedral