Physical Properties of Magnetite Nanoparticles Covered by 11-Mercaptoundecanoic Acid
M. Timkoa, P. Kopčanskýa, M. Antalika, M. Simsikovab, E. Valusovaa, M. Molcana and J. Kováča
aInstitute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice, Slovakia
bDepartment of Biochemistry, Faculty of Sciences UPJS, Moyzesova 11, 041 54 Kosice, Slovakia
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We have investigated the magnetic behavior of magnetite nanoparticles covered by the 11-mercaptoundecanoic acid around magnetite core prepared by a standard co-precipitation method. The particles show superparamagnetic behavior at room temperature, with transition to a blocked state at blocking temperature 91 K estimated from zero field cooled and field cooled at 500 Oe experiment. The hysteresis loop measured at 293 K showed magnetization 32.8 emu/g at 50 kOe without any coercivity. The mean particle size (7.1 nm) was determined by fitting a magnetization curve obtained at 295 K assuming a log-normal size distribution.
DOI: 10.12693/APhysPolA.121.1321
PACS numbers: 47.65.Cb, 85.70.-w, 75.30.Cr, 75.47.Lx