Vertically Aligned Single-Crystalline CoFe<sub>2</sub>O<sub>4</sub> Nanobrush Architectures with High Magnetization and Tailored Magnetic Anisotropy

Micrometer-tall vertically aligned single-crystalline CoFe<sub>2</sub>O<sub>4</sub> nanobrush architectures with extraordinarily large aspect ratio have been achieved by the precise control of a kinetic and thermodynamic non-equilibrium pulsed laser epitaxy process. Direct ob...

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Bibliographic Details
Main Authors: Lisha Fan, Xiang Gao, Thomas O. Farmer, Dongkyu Lee, Er-Jia Guo, Sai Mu, Kai Wang, Michael R. Fitzsimmons, Matthew F. Chisholm, Thomas Z. Ward, Gyula Eres, Ho Nyung Lee
Format: Article
Language:English
Published: MDPI AG 2020-03-01
Series:Nanomaterials
Subjects:
Online Access:https://www.mdpi.com/2079-4991/10/3/472
Description
Summary:Micrometer-tall vertically aligned single-crystalline CoFe<sub>2</sub>O<sub>4</sub> nanobrush architectures with extraordinarily large aspect ratio have been achieved by the precise control of a kinetic and thermodynamic non-equilibrium pulsed laser epitaxy process. Direct observations by scanning transmission electron microscopy reveal that the nanobrush crystal is mostly defect-free by nature, and epitaxially connected to the substrate through a continuous 2D interface layer. In contrast, periodic dislocations and lattice defects such as anti-phase boundaries and twin boundaries are frequently observed in the 2D interface layer, suggesting that interface misfit strain relaxation under a non-equilibrium growth condition plays a critical role in the self-assembly of such artificial architectures. Magnetic property measurements have found that the nanobrushes exhibit a saturation magnetization value of 6.16 B/f.u., which is much higher than the bulk value. The discovery not only enables insights into an effective route for fabricating unconventional high-quality nanostructures, but also demonstrates a novel magnetic architecture with potential applications in nanomagnetic devices.
ISSN:2079-4991