Nanocomposites and nanomaterials
Features of dispersion of dimensional and magnetic parameters in spinel ferrite nanoparticles
Zamorskyi V. O.1, Solopan S. O.2, Belous A. G.2, Tovstolytkin A. I.1
1 Institute of Magnetism of the NAS of Ukraine and MES of Ukraine,
36b Academician Vernadsky Blvd., UA-03142 Kyiv, Ukraine
E-mail: 0vl0ad0@gmail.com
2 V.I. Vernadsky Institute of General and Inorganic Chemistry of the NAS of Ukraine, 32/34 Academician Palladin Ave., UA-03142 Kyiv, Ukraine

Magnetic nanoparticles (MNPs) have been used in many important technological applications such as ultra-high density magnetic recording and data storage, highly sensitive magnetic sensors, permanent magnets and various biomedical applications, which are of a great interest nowadays [1]. Here, we suggest the ways to account for the dispersion of size and magnetic parameters, and adequately predict the behavior of MNP ensembles under various conditions. 
AFe2O4 (A = Ni, Zn, Co) MNPs were synthesized by precipitation from non-aqueous solutions as described in [2]. Unfortunately, the synthesized NMPs do not have a uniform size distribution, and this may significantly affect their widespread use, since obtaining monodispersed nanoparticles requires a complicated additional step, which increases production cost. Thus, it is of a paramount importance to develop a relatively simple approach to predict the behavior of such NMPs under different external factors.
The analysis of the magnetization curves of nanopowders displaying superparamagnetic-like behavior has been performed. The distribution functions of MNPs in terms of magnetic moment and size have been determined. It is shown that the size distribution function obtained from the magnetic characteristics makes it possible to adequately describe the behavior of an ensemble of nanoparticles containing weakly magnetic or nonmagnetic shells. As concluded, the proposed approach is effective for analyzing the dispersion of the dimensional and magnetic parameters of nanoparticle ensembles and for predicting their behavior under the influence of electro-magnetic fields.

1.	Leena Mohammed, Hassan G. Gomaa, Doaa Ragab, Jesse Zhu. Magnetic nanoparticles for environmental and biomedical applications: A review // Particuology.-2017.-30.-P. 1-14.
2.	Yelenich O.V., Solopan S.O., Kolodiazhnyi T.V., Dzyublyuk V.V., Tovstolytkin A.I., Belous A.G. Superparamagnetic behavior and AC-losses in NiFe2O4 nanoparticles // Solid State Sciences.-2013.-20.-P. 115-119.