Relaxation behaviour of Co and Ni implanted into MgO (original) (raw)

Doping magnesium oxide with cobalt and nickel by ion implantation, results in the formation of nanosized metallic clusters [Pinto, et al., Eur. Phys. J. B 45 (2005) 331]. Single crystals of [1 0 0] MgO were implanted with the transition ions, Co and Ni, with 250 keV energy and fluence of 1 Â 10 17 cm À2. After vacuum annealing at 1270 K the implanted samples exhibit superparamagnetic behaviour associated with the formation of metallic clusters. The magnetic relaxation of these clusters was studied using magnetization measurements, in order to characterize the nanosized aggregates.