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Chai K, Li ZA, Huang W, Richter G, Liu R, Zou B, Caron J, Kovács A, Dunin-Borkowski RE, Li J. Magnetic quantification of single-crystalline Fe and Co nanowires via off-axis electron holography. J Chem Phys 2020; 152:114202. [PMID: 32199423 DOI: 10.1063/1.5145337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Investigating the local micromagnetic structure of ferromagnetic nanowires (NWs) at the nanoscale is essential to study the structure-property relationships and can facilitate the design of nanostructures for technology applications. Herein, we synthesized high-quality iron and cobalt NWs and investigated the magnetic properties of these NWs using off-axis electron holography. The Fe NWs are about 100 nm in width and a few micrometers in length with a preferential growth direction of [100], while the Co NWs have a higher aspect-ratio with preferential crystal growth along the [110] direction. It is noted that compact passivation surface layers of oxides protect these NWs from further oxidation, even after nearly two years of exposure to ambient conditions; furthermore, these NWs display homogeneous ferromagnetism along their axial direction revealing the domination of shape anisotropy on magnetic behavior. Importantly, the average value of magnetic induction strengths of Fe NWs (2.07 {±} 0.10 T) and Co NWs (1.83 {±} 0.15 T) is measured to be very close to the respective theoretical value, and it shows that the surface oxide layers do not affect the magnetic moments in NWs. Our results provide a useful synthesis approach for the fabrication of single-crystalline, defect-free metal NWs and give insight into the micromagnetic properties in ferromagnetic NWs based on the transmission electron microscopy measurements.
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Affiliation(s)
- Ke Chai
- Beijing Key Laboratory of Nano Photonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Zi-An Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Wenting Huang
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
| | - Gunther Richter
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
| | - Ruibin Liu
- Beijing Key Laboratory of Nano Photonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Bingsuo Zou
- Beijing Key Laboratory of Nano Photonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jan Caron
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - András Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Jianqi Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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