REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

aNALYSIS OF ZFC/FC CURVES OF HEMATITE-SILICA NANOCOMPOSITE MATERIALS

VIOLETA N. NIKOLIĆ

Institute of Nuclear Sciences Vinča, University of Belgrade, Mike Petrovića Alasa 12-14, P. O. Box 522, 11001 Belgrade, violeta@vinca.rs

VOJISLAV SPASOJEVIĆ

Institute of Nuclear Sciences Vinča, University of Belgrade, Mike Petrovića Alasa 12-14, P. O. Box 522, 11001 Belgrade, vojas@vinca.rs

Abstract: Composite materials containing hematite and silica nanoparticles are recognized as a suitable electromagnetic waves absorbers, which is of importance for various military applications. To improve quality of absorbers based on hematite-silica nanocomposite materials, it is necessary to achieve better understanding of hematite nanoparticles magnetic properties. In this study, α-Fe₂O₃ nanoparticles embedded in the silica matrix are prepared by the sol-gel method. The silica matrix is used in order to reduce the influence of strong interparticle interactions. XRD analysis shows that the mean crystallite size of hematite is 11 nm. Magnetic analysis comprised zero-field cooled and field-cooled (ZFC/FC) measurements of temperature dependent magnetization and magnetic susceptibility, since the acquisition of the mentioned curves, following the ZFC/FC protocol, presents a common tool to examine the magnetic behavior of the investigated nanocomposite material.

Keywords: hematite-silicananocomposite ZFC/FC measurements.