Universität zu Köln

Disch, Sabrina ORCID: 0000-0002-4565-189X, Hermann, R. P., Wetterskog, E., Podlesnyak, A. A., An, K., Hyeon, T., Salazar-Alvarez, G., Bergstrom, L. and Brueckel, Th. (2014). Spin excitations in cubic maghemite nanoparticles studied by time-of-flight neutron spectroscopy. Phys. Rev. B, 89 (6). COLLEGE PK: AMER PHYSICAL SOC. ISSN 1550-235X

Full text not available from this repository.

Abstract

We have determined the field dependence of collective magnetic excitations in iron oxide nanoparticles of cubic shape with 8.42(2) nm edge length and a narrow log normal size distribution of 8.2(2)% using time-of-flight neutron spectroscopy. The energy dependence of the uniform precession modes was investigated up to 5 T applied field and yields a Lande factor g = 2.05(2) as expected for maghemite (gamma-Fe2O3) nanoparticles. A large effective anisotropy field of B-A,B-eff = 0.45(16) T was determined, in excellent agreement with macroscopic measurements. This anisotropy is attributed to enhanced shape anisotropy in these monodisperse cubic nanoparticles. The combination of our results with macroscopic magnetization information provides a consistent view of the energy scales of superparamagnetic relaxation and collective magnetic excitations in magnetic nanoparticles.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Disch, Sabrina UNSPECIFIED orcid.org/0000-0002-4565-189X UNSPECIFIED Hermann, R. P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wetterskog, E. UNSPECIFIED UNSPECIFIED UNSPECIFIED Podlesnyak, A. A. UNSPECIFIED UNSPECIFIED UNSPECIFIED An, K. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hyeon, T. UNSPECIFIED UNSPECIFIED UNSPECIFIED Salazar-Alvarez, G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Bergstrom, L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Brueckel, Th. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-446029
DOI:	10.1103/PhysRevB.89.064402
Journal or Publication Title:	Phys. Rev. B
Volume:	89
Number:	6
Date:	2014
Publisher:	AMER PHYSICAL SOC
Place of Publication:	COLLEGE PK
ISSN:	1550-235X
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Physical Chemistry
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language MAGNETIC NANOPARTICLES; MOSSBAUER-SPECTRA; SCATTERING; DYNAMICS; PARTICLES; NANOCRYSTALS; GAMMA-FE2O3 Multiple languages Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/44602