Preparation and properties of noble metal/magnetite composite nanoparticles

G. Kronkalns¹ - M. M.Maiorov¹ - V. Serga² - A. Krumina² - D. Karashanova³

¹ Institute of Physics, University of Latvia, 32 Miera, Salaspils, LV- 2169, Latvia
² Institute of Inorganic Chemistry, Riga Technical University, 34 Miera, Salaspils, LV-2169, Latvia
³ Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, 109 Acad. G. Bonchev, 1113 Sofia, Bulgaria

Abstract
Composite magnetic nanoparticles containing magnetite and noble Pt or Au metals in each particle were produced with the aim to create a new type of material, which can be manipulated by an external magnetic field. Composite nanoparticles composed o f platinum or gold and magnetite \Fe ₃Ø ₄ were produced by the extractive-pyrolytic method (EPM), which allows to quickly and simply obtain a composition of the noble metal nanoparticles on magnetite. The dependence of composite physical properties on the morphology, content and size of the noble metals was studied. The phase composition, the size and the magnetic properties of all samples were investigated using an X-ray diffractometer, a transmission electron microscope and a vibrating sample magnetometer, respectively. The possibility to produce a magnetic colloid using the Fe₃O₄/Pt composite as a dispersed medium was illustrated. Tables 1, Figs 6, Refs 15.