Magnetism in Cobalt Clusters

We have measured the magnetic moments of cobalt clusters, ranging in size from $<$10 to 200 atoms. Improvements to our cluster source have allowed us to produce smaller and colder ($\sim $60K) clusters than we were able to study in previous work, and to study each cluster size individually. We will present measured values for the magnetic moments of these clusters as functions of size, temperature, and applied field. We have also investigated the superparamagnetic behaviors of cobalt clusters, looking for deviations from that behavior. Applications of this work in the area of magnetic data recording will be discussed. This presentation is based upon work supported by the National Science Foundation under Grant No. DMR-0405203.