title: The magnetic moment of NiO nanoparticles determined by Mössbauer spectroscopy.
abstract: We have studied the magnetic properties of (57)Fe-doped NiO nanoparticles using Mössbauer spectroscopy and magnetization measurements. Two samples with different degrees of interparticle interaction were studied. In both samples the particles were characterized by high-resolution transmission electron microscopy and x-ray diffraction and found to be plate-shaped. Computer simulations showed that high-field Mössbauer data are very sensitive to the size of the uncompensated magnetic moment. From analyses of the Mössbauer spectra we have estimated that the size of the uncompensated magnetic moment is in accordance with a model based on random occupation of surface sites. The analyses of the magnetization data gave larger magnetic moments, but the difference can be explained by the different sensitivity of the two methods to a particle size distribution and by interactions between the particles, which may have a strong influence on the moments estimated from magnetization data.
authors.affiliation: Department of Physics, Building 307, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark. Materials Research Department, Building 227, Risø National Laboratory, DK-4000 Roskilde, Denmark.
authors.forename: C R H
authors.initials: CR
authors.lastname: Bahl
authors.forename: M F
authors.initials: MF
authors.lastname: Hansen
authors.forename: T
authors.initials: T
authors.lastname: Pedersen
authors.forename: S
authors.initials: S
authors.lastname: Saadi
authors.forename: K H
authors.initials: KH
authors.lastname: Nielsen
authors.forename: B
authors.initials: B
authors.lastname: Lebech
authors.forename: S
authors.initials: S
authors.lastname: Mørup