H-1-NMR study of the spin dynamics of fine superparamagnetic nanoparticles

TitleH-1-NMR study of the spin dynamics of fine superparamagnetic nanoparticles
Publication TypeJournal Article
Year of Publication2012
AuthorsBordonali L, Furukawa Y, Kraken M, Litterst FJ, Sangregorio C, Casula MF, Lascialfari A
Journal TitlePhysical Review B
Volume85
Pages174426
Date Published05
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000304172500003
Keywordsgamma-fe2o3 nanoparticles, NUCLEAR MAGNETIC RELAXATION, size, surface, temperature
Abstract

We report a broadband H-1-NMRstudy of the temperature spin dynamics of nearly monodisperse dextran-coated gamma-Fe2O3 magnetic nanoparticles. We observed a maximum in T-1(-1) (T) that decreases in amplitude and shifts toward higher temperatures with increasing field. We suggest that this is related to the progressive superparamagnetic spin blocking of the ferrite core. The data can be explained by assuming a single electronic spin-spin correlation time and introducing a field-dependent distribution of anisotropy energy barriers.

URL<Go to ISI>://WOS:000304172500003
DOI10.1103/PhysRevB.85.174426
Alternate JournalPhys. Rev. B