Dipolar magnetism in assembled Co nanoparticles on graphene. Issue 31 (30th July 2018)

• Record Type: Journal Article
• Authors: Chan, Yao-Jui; Huang, Chih-Heng; Chang, Yin-Ming; Lu, Yi-Ying; Wu, Shih-Yu; Wei, Der-Hsin; Kuo, Chien-Cheng
• Is Part Of: Physical chemistry chemical physics. Volume 20:Issue 31(2018)
• Page Start: 20629
• Page End: 20634
• Publication Date: 2018-07-30
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c8cp03145b
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The magnetic properties of the assembled Co nanoparticles on graphene were studied using X-ray magnetic circular dichroism (XMCD), magneto-optical Kerr effects, and a modeling simulation. Abstract : The magnetic properties of the assembled Co nanoparticles on graphene were studied using X-ray magnetic circular dichroism (XMCD), magneto-optical Kerr effects, and a modeling simulation. We demonstrate that the superparamagnetic nanoparticles reveal a ferromagnetic phase when they are assembled on graphene. The moderate increase of the XMCD asymmetry and magnetization with coverage for this assembly indicates a dipolar-mediated magnetism, which is further verified by a model simulation considering the dipolar interaction between neighboring nanoparticles. Furthermore, C K-edge spectra reveal visible dichroism at the π* state of graphene, which indicates the existence of a spin-polarized interface state, while the assembled Co nanoparticles reveal a ferromagnetic phase. These results suggest an efficient route to stabilize the ferromagnetic phase of nanostructures on graphene by tailoring dipolar interactions, which is essential to realize a higher efficiency of spin injection in graphene-based spintronics.