Magnetic behavior of iron (III) oxyhydroxy nanoparticles in organic-inorganic hybrid matrices

authors	Silva, NJO; Amaral, VS; Carlos, LD; Fu, LS; Nunes, SC; Bermudez, VD
nationality	International
journal	JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
author keywords	antiferromagnetism; nanoparticles; polymers; sol-gel method
keywords	NANOHYBRIDS; UREA
abstract	Magnetic properties of iron(III) oxyhydroxy nanoparticles stabilized within a sol-gel derived organic-inorganic matrix are investigated. Depending on the size of the polymer chain and on the sol-gel route, ferrihydrite or Fe(III) oxyhydroxynitrate can be formed. Comparing different sets of samples we can address the observed magnetic features to the different oxyhydroxy phases. The ferrihydrite particles exhibit thermal and field irreversibility below 30 K, with coercive and exchange fields characteristic of antiferromagnetic nanoparticles uncompensated/canted spins. The existence of anti ferromagnetic interactions in the Fe(III) oxyhydroxynitrate phase can be inferred. (c) 2004 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0304-8853
year published	2005
volume	290
beginning page	962
ending page	965
digital object identifier (doi)	10.1016/j.jmmm.2004.11.301
web of science category	Materials Science, Multidisciplinary; Physics, Condensed Matter
subject category	Materials Science; Physics
unique article identifier	WOS:000228837900045