Magnetic properties of CoO nanoparticles

Abstract.

The magnetic circular X-ray dichroism (MCXD) of CoO nanoparticles was measured at low temperatures and in high magnetic fields. The particles show a superparamagnetic behaviour at room temperature, and a large orbital contribution to the magnetic moment at low temperatures was observed. This enhancement of orbital magnetism is largely determined by the contribution of the surface atoms. The larger spin–orbit coupling of the electrons of the surface atoms of the particle can cause a change in magnetic ordering in the core of the particles.