Superparamagnetic blocking of an ensemble of magnetite nanoparticles upon interparticle interactions
URI (for links/citations):http://www.sciencedirect.com/science/article/pii/S0304885316331390
Balaev, D. A.
Semenov, S. V.
Dubrovskiy, A. A.
Yakushkin, S. S.
Kirillov, V. L.
Martyanov, O. N.
Институт инженерной физики и радиоэлектроники
Кафедра общей физики
Journal Name:Journal of Magnetism and Magnetic Materials
Journal Quartile in Scopus:Q1
Journal Quartile in Web of Science:Q2
Bibliographic Citation:Balaev, D. A. Superparamagnetic blocking of an ensemble of magnetite nanoparticles upon interparticle interactions [Текст] / D. A. Balaev, S. V. Semenov, A. A. Dubrovskiy, S. S. Yakushkin, V. L. Kirillov, O. N. Martyanov // Journal of Magnetism and Magnetic Materials. — 2017. — Т. 440. — С. 199-202
We report on the eﬀect of interparticle magnetic interactions in an ensemble of superparamagnetic magnetite particles with an average size of ~8.4 nm dispersed in the diamagnetic matrix on the blocking of this ensemble in external magnetic ﬁeld. The two limit cases are investigated: the case of strongly interacting particles, when the value of magnetic dipole-dipole interaction between particles is comparable with the energy of other interactions in the ensemble (the interparticle distance is similar to the nanoparticle diameter) and the case of almost noninteracting particles distant from each other by about ten particle diameters. We demonstrate that the experimental dependence of the blocking temperature on external ﬁeld is described well within the model , in which the density of particles in a nonmagnetic medium is taken into account and the correlation value depends on external magnetic ﬁeld. The model for describing the magnetic properties of a disperse nanoparticle ensemble is proposed, which makes corrections related to the particle size and mean dipole-dipole interaction energy for the anisotropy constant. The surface magnetic anisotropy of Fe3O4 particles and parameters of the interparticle coupling are estimated