Direct evidence for ferromagnetic spin polarization in gold nanoparticles

TL;DR

This paper provides direct experimental evidence of intrinsic ferromagnetic spin polarization in gold nanoparticles of about 1.9 nm diameter, using element-specific XMCD measurements that align with magnetometry results.

Contribution

It is the first to directly observe ferromagnetic spin polarization in gold nanoparticles, demonstrating intrinsic magnetism at the nanoscale.

Findings

Gold nanoparticles exhibit ferromagnetic spin polarization.

XMCD measurements confirm gold's magnetization.

Results align with conventional magnetometry data.

Abstract

We report the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms estimated by XMCD shows a good agreement with the results obtained by conventional magnetometry. This result is evidence of intrinsic spin polarization in nano-sized gold.