Selectable Spontaneous Polarization Direction and Magnetic Anisotropy in BiFeO3−CoFe2O4 Epitaxial Nanostructures

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• 作者：Nico Dix ; Rajaram Muralidharan ; Jose-Manuel Rebled ; Sonia Estradé ; Francesca Peiró ; Manuel Varela ; Josep Fontcuberta ; Florencio Sánchez
• 刊名：ACS Nano
• 出版年：2010
• 出版时间：August 24, 2010
• 年：2010
• 卷：4
• 期：8
• 页码：4955-4961
• 全文大小：504K
• 年卷期：0
• ISSN：1936-086X

文摘

We demonstrate that epitaxial strain engineering is an efficient method to manipulate the ferromagnetic and ferroelectric properties in BiFeO₃−CoFe₂O₄ columnar nanocomposites. On one hand, the magnetic anisotropy of CoFe₂O₄ is totally tunable from parallel to perpendicular controlling the CoFe₂O₄ strain with proper combinations of substrate and ferroelectric phase. On the other hand, the selection of the used substrate allows the growth of the rhombohedral bulk phase of BiFeO₃ or the metastable nearly tetragonal one, which implies a rotation of the ferroelectric polar axis from [111] to close to the [001] direction. Remarkably, epitaxy is preserved and interfaces are semicoherent even when lattice mismatch is above 10%. The broad range of sustainable mismatch suggests new opportunities to assemble epitaxial nanostructures combining highly dissimilar materials with distinct functionalities.