Magnetic nanostructures as amplifiers of transverse fields in magnetic resonance.
We introduce the concept of amplifying the transverse magnetic fields produced and/or detected with inductive coils in magnetic resonance settings by using the reversible transverse susceptibility properties of magnetic nanostructures. First, we describe the theoretical formalism of magnetic flux amplification through the coil in the presence of a large perpendicular DC magnetic field (typical of magnetic resonance systems) achieved through the singularity in the reversible transverse susceptibility in anisotropic single domain magnetic nanoparticles. We experimentally demonstrate the concept of transverse magnetic flux amplification in an inductive coil system using oriented nanoparticles with uni-axial magnetic anisotropy. We also propose a composite ferromagnetic/anti-ferromagnetic core/shell nanostructure system with uni-directional magnetic anisotropy that, in principle, provides maximal transverse magnetic flux amplification.
Barbic
Mladen
M
Department of Physics and Astronomy, Peterson Hall 3 Office 019, California State University, Long Beach, 1250 Bellflower Boulevard, Long Beach, CA 90840, USA. mbarbic@csulb.edu
Scherer
Axel
A