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Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

SYSNO ASEP	0450283
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium
Author(s)	Smolkova, I.S. (CZ) Kazantseva, N.E. (CZ) Babayan, V. (CZ) Smolka, P. (CZ) Parmar, H. (CZ) Vilcakova, J. (CZ) Schneeweiss, Oldřich (UFM-A)_{RID, ORCID} Pizúrová, Naděžda (UFM-A)_{RID, ORCID}
Number of authors	8
Source Title	Journal of Magnetism and Magnetic Materials. - : Elsevier - ISSN 0304-8853 Roč. 374, JAN (2015), s. 508-515
Number of pages	8 s.
Language	eng - English
Country	NL - Netherlands
Keywords	Iron oxide nanoparticles ; Coprecipitation ; Magnetic interactions ; Specific loss power ; Hyperthermia
Subject RIV	BM - Solid Matter Physics ; Magnetism
Institutional support	UFM-A - RVO:68081723
UT WOS	000344949000082
EID SCOPUS	84907279771
DOI	10.1016/j.jmmm.2014.08.096
Annotation	Magnetic iron oxide nanoparticles were obtained by a coprecipitation method in a controlled growth process leading to the formation of uniform highly crystalline nanoparticles with average size of 13 nm, which corresponds to the superparamagnetic state. Nanoparticles obtained are a mixture of single-phase nanoparticles of magnetite and maghemite as well as nanoparticles of non-stoichiometric magnetite. The subsequent annealing of nanoparticles at 300 degrees C in air during 6 h leads to the full transformation to maghemite. It results in reduced value of the saturation magnetization (from 56 emu g(-1) to 48 emu g(-1) but does not affect the healing ability of nanoparticles. A 2-7 wt% dispersion of as-prepared and annealed nanoparticles in glycerol provides high healing rate in alternating magnetic fields allowed for application in magnetic hyperthermia; however the value of specific loss power does not exceed 30 W g(-1). This feature of heat output is explained by the combined effect of magnetic interparticle interactions and the properties of the carrier medium. Nanoparticles coalesce during the synthesis and form aggregates showing ferromagnetic-like behavior with magnetization hysteresis, distinct sexes on Mossbauer spectrum, blocking temperature well about room temperature, which accounts for the higher energy barrier for magnetization reversal. At the same time, low specific heat capacity of glycerol intensifies heat transfer in the magnetic dispersion. However, high viscosity of glycerol limits the specific loss power value, since predominantly the Neel relaxation accounts for the absorption of AC magnetic field energy.
Workplace	Institute of Physics of Materials
Contact	Yvonna Šrámková, sramkova@ipm.cz, Tel.: 532 290 485
Year of Publishing	2016

Number of the records: 1