Regular Article

Magnetic study of Fe₃O₄/Ag nanoparticles

¹ Institute of Physics, West Pomeranian University of Technology, 48 Piastow Str., 70-311 Szczecin, Poland
² Institute of Chemical and Environment Engineering, Faculty of Chemical Technology and Engineering, Pułaskiego 10, 70-322 Szczecin, Poland

^* e-mail: typjan@zut.edu.pl

Received: 22 October 2017
Received in final form: 26 June 2018
Accepted: 16 July 2018
Published online: 18 October 2018

Abstract

Nanocomposites of Fe₃O₄ nanoparticles (NPs) impregnated with silver NPs display antibacterial properties and may be used in water treatment as disinfection agent. Three samples were synthesized: Fe₃O₄ NPs obtained by the precipitation method and additionally two samples with added silver NPs with mass ratio of Ag:Fe₃O₄ equal to 1:100 and 2:100. Magnetic properties of these samples were studied by SQUID magnetometry (in temperature range 2–300 K and magnetic fields up to 70 kG) and magnetic resonance technique at RT. Temperature dependence of dc susceptibility revealed the blocking temperature close to RT in all three samples and allowed to determine the presence of single or multi-mode distribution of NP sizes in a particular sample. Isothermal magnetisation measurements showed that the presence of silver NPs, especially those with smaller sizes, decreases the saturation magnetisation. The shape of ferromagnetic loop registered at T = 2 K was used to discuss the sizes of NP magnetic clusters in our samples. Conclusions obtained from analysis of the ferromagnetic resonance spectra were consistent with the propositions based on the magnetometric studies.