Influence of Nanocrystalline Ferrite Particles on Properties of Magnetic Systems

Nanocrystalline mainly superparamagnetic ferrite particles ≈ 10nm are used for the preparation of magnetic fluids. Barium hexaferrite BaFe12−2x TixCoxO19 powders with mean particle sizes < 30nm show the transition to single domain Stoner- Wohlfarth behaviour. Hysteresis parameters, losses and the initial susceptibility versus temperature were obtained by VSM. Ba-ferrite ferrofluids have been prepared using Isopar M or dodecane as carrier liquid. Small Angle Neutron Scattering curves lead to a bimodal size distribution consisting of single magnetic particles and aggregated magnetic particles. Particle size investigations were done by TEM.