Microscale magnetic compasses

Autor(en)

Hidetsugu Shiozawa, Desai Zhang, Michael Eisterer, Paola Ayala, Thomas Pichler, Martha R. McCartney, David J. Smith

Abstrakt

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.

Organisation(en)

Elektronische Materialeigenschaften

Externe Organisation(en)

Arizona State University, Technische Universität Wien, Czech Academy of Sciences

Journal

Journal of Applied Physics

Band

122

Anzahl der Seiten

6

ISSN

0021-8979

DOI

https://doi.org/10.1063/1.4985838

Publikationsdatum

09-2017

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik, 103009 Festkörperphysik, 103020 Oberflächenphysik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4f755d18-da02-411d-81d5-918c8b12ce9c