Microscale magnetic compasses
| Autor: | Michael Eisterer, Desai Zhang, Hidetsugu Shiozawa, Martha R. McCartney, Paola Ayala, Thomas Pichler, David J. Smith |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Magnetic domain Condensed matter physics Demagnetizing field General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Magnetic susceptibility 0104 chemical sciences Magnetic field Magnetic anisotropy Paramagnetism Nuclear magnetic resonance Magnet 0210 nano-technology Saturation (magnetic) |
| Zdroj: | Journal of Applied Physics. 122:094301 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4985838 |
| Popis: | Microscale magnetic compasses have been synthesized with high yield. These ferromagnetic iron carbide nano-particles, which are encapsulated in a pair of parallel carbon needles, change their orientation in response to an external magnetic field. Electron holography reveals magnetic fields confined to the vicinity of the bicone-shaped particles, which are composed of only a few ferromagnetic domains. Aligned magnetically and encapsulated in an acrylate polymer matrix, these micro-compasses exhibit anisotropic bulk magnetic permeability with an easy axis normal to the needle direction that can be understood as a result of the anisotropic demagnetizing field of a non-spherical single-domain particle. This novel type of material with orthogonal magnetic and structural axes could be highly useful as magnetic components in electromagnetic wave absorbent materials and magnetorheological fluids. |
| Databáze: | OpenAIRE |
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