US Patent 7186398 - Fe/Au nanoparticle

http://www.freepatentsonline.com/7186398.pdf

This patent from Purdue Research proposes a new paramagnetic nanoparticle in which the magnetic moment can be precisely controlled and which can be readily modified by attachment of selected organic molecules to their surfaces. Claim 1 reads:

1. A superparamagnetic nanoparticle comprising Fe atoms and Au atoms distributed in a solid solution with no observable segregation into Fe-rich or Au-rich phases or regions.