Magnetic properties of maghemite nanoparticle system: surface anisotropy and interactions

The static and dynamic magnetic properties of powders of maghemite nanoparticles with average diameter D = 2.7,4.6 and 8.7 nm have been investigated by magnetisation, AC susceptibility at variable frequency (5-104 Hz) and Mossbauer spectroscopy measurements. The results provide an insight into the correlation between intra-particle and inter-particle effects.