Bulk magnetization and H-1 NMR spectra of magnetically heterogeneous model systems

TitleBulk magnetization and H-1 NMR spectra of magnetically heterogeneous model systems
Publication TypeJournal Article
Year of Publication2011
AuthorsLevin EM, Bud'ko SL
Journal TitleJournal of Magnetism and Magnetic Materials
Volume323
Pages2355-2361
Date Published10
ISBN Number0304-8853
Accession NumberISI:000291425100004
Keywordsbulk magnetization, HECTORITE, iron-oxide nanoparticles, layered silicates, magnetically heterogeneous system, nanocomposites, nuclear magnetic resonance, organometallic complexes, particles, resolution, resonance spectra, solids, state nmr-spectroscopy
Abstract

Bulk magnetization and H-1 static and magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of two magnetically heterogeneous model systems based on laponite (LAP) layered silicate or polystyrene (PS) with low and high proton concentration, respectively, and ferrimagnetic Fe2O3 nano-or micro-particles have been studied. In LAP+ Fe2O3, a major contribution to the NMR signal broadening is due to the dipolar coupling between the magnetic moments of protons and magnetic particles. In PS+ Fe2O3, due to the higher proton concentration in polystyrene and stronger proton-proton dipolar coupling, an additional broadening is observed, i.e. H-1 MAS NMR spectra of magnetically heterogeneous systems are sensitive to both proton-magnetic particles and proton-proton dipolar couplings. An increase of the volume magnetization by similar to 1 emu/cm(3) affects the H-1 NMR signal width in a way that is similar to an increase of the proton concentration by similar to 2 x 10(22)/cm(3). H-1 MAS NMR spectra, along with bulk magnetization measurements, allow the accurate determination of the hydrogen concentration in magnetically heterogeneous systems. (C) 2011 Elsevier B.V. All rights reserved.

URL<Go to ISI>://000291425100004
DOI10.1016/j.jmmm.2011.04.011
Alternate JournalJ Magn Magn MaterJ Magn Magn Mater