Preparation and magnetic properties of oxide-coated monodispersive Co cluster assembly

Oxide-coated monodispersive Co duster assemblies with the mean cluster size of 6 and 13 nm have been prepared by a plasma-gas-condensation type cluste r beam deposition apparatus. The magnetic properties of the samples prepare d without and with introducing oxygen gas into the deposition chamber are c ompared. The exchange anisotropy induced by interfacial exchange coupling b etween the ferromagnetic Co core and the antiferromagnetic cobalt oxide she ll has been studied by measuring the hysteresis loop shift of the field-coo led samples and the low field thermomagnetic curve.