Anomalous magnetic polarization effect of Pd and Au nano-particles

The magnetization of Pd and Au nano-particles with a diameter of around 3 n m was measured down to 4.2 K. The data of magnetization of both nano-partic les show an unexpectedly large magnetic moment of about 20 spins per partic le. This result can not be understood by so-called odd/even electron number effect and Stoner's enhancement model. The result might suggest the existe nce of some common and characteristic spin correlation mechanism in the nan o-particles. The experimental result of size dependence on Pd nano-particle s shows existence of a critical size of about 3 nm from a atomic spin corre lation region to a metallic spin correlation region. (C) 1999 Published by Elsevier Science B.V. All rights reserved.