Neutron diffraction and magnetism of CoO antiferromagnetic nanoparticles

authors	Silva, NJO; Puente-Orench, I; Martins, M; Trindade, T; Millan, A; Campo, J; Palacio, F
editors	Gorria, P; Blanco, JA
nationality	International
journal	5TH MEETING OF THE SPANISH NEUTRON SCATTERING ASSOCIATION
keywords	MAGNETIZATION; TEMPERATURE
abstract	We report a study on neutron diffraction and magnetic properties of cobalt oxide CoO antiferromagnetic nanoparticles with different sizes. The nanoparticles are composed by a structurally and magnetically ordered core and a structurally ordered and magnetically disordered shell with a thickness of about 2 nm. The ordered core has cell parameters, moments direction and modulus similar to those of bulk CoO. Small differences found are attributed to an increase of the oxidation of the nanoparticles with the decrease of size. A remanent moment M-r can be induced in CoO nanoparticles by crossing the transition temperature in the presence of a magnetic field, while the magnetic structure of the antiferromagnetically ordered moments of then a noparticles core remains unchanged after field cooling within the experimental precision, suggesting that M-r arises in the magnetically disordered shell.
publisher	IOP PUBLISHING LTD
issn	1742-6588
year published	2011
volume	325
digital object identifier (doi)	10.1088/1742-6596/325/1/012020
web of science category	Materials Science, Multidisciplinary; Physics, Nuclear
subject category	Materials Science; Physics
unique article identifier	WOS:000299526300020