• Single nanosized magnetic particles are mono-domains and one expects that
also in magnetic nanophase materials the grains correspond with domains,
while boundaries on the contrary to disordered walls. Very small particles have
special atomic structures with discrete electronic states, which give rise to
special properties in addition to the super-paramagnetism behaviour. Magnetic
nano-composites have been used for mechanical force transfer (ferrofluids),
for high density information storage and magnetic refrigeration.