Magnetic nanostructures as amplifiers of transverse fields in magnetic resonance

• Published in: Solid state nuclear magnetic resonance Vol. 28; no. 2; pp. 91 - 105
• Main Authors: Barbic, Mladen, Scherer, Axel
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.09.2005
• Subjects: Magnetic nanoparticles; Magnetic nanostructures; Magnetic resonance; Magnetic resonance microscopy; Magnetic resonance spectroscopy; Magnetic susceptibility; Signal-to-noise ratio; Magnetic resonance spectroscopy; Magnetic resonance; Magnetic nanoparticles; Signal-to-noise ratio; Magnetic nanostructures; Magnetic resonance microscopy; Magnetic susceptibility
• ISSN: 0926-2040; 1527-3326
• DOI: 10.1016/j.ssnmr.2005.06.002

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.