Direct Observation of the Ferromagnetic Spin Polarization in Gold Nanoparticles

摘要

We review the magnetic properties of noble metal nanoparticles protected by polymers and the first direct evidence of the intrinsic ferromagnetism of Au nanoparticles protected by polyallyl amine hydrochloride (PAAHC) by means of element-specific magnetization (ESM) measured by X-ray magnetic circular dichroism (XMCD) spectroscopy. Unlike conventional methods, XMCD can detect magnetic moments in an element-specific manner because it is sensitive to differences between the up- and down-spin densities near the Fermi level of specific element of interest.