Abstract
Ferromagnetic spin polarizations on the samples of Au nanoparticles surrounded by protectives were observed by MCD method on X-ray (XMCD) of Au L3-edgge to investigate the origin of the spin polarization. The consistency between both magnetization data by SQUID and XMCD are quite well and the result means that the observed magnetization is originated from the Au-nanoparticle itself. The protectives make some slight effect on the magnetization, but the protective of DT (Dodecane thiol) makes quite big reduction of the magnetization. The protective dependence directly means that the origin of the spin polarization arises from the surface of the nanoparticles. Diameter dependence of the surface magnetization on Au-nanoparticles is linearly decreasing with increasing diameter and the data sharply close to the value of bulk state Au-metal at the diameter of 4 nm. The results also make us infer close relation between surface and magnetization and the possibility of wide applications of nanosized materials.
