X-ray magnetic circular dichroism study of the blocking process in nanostructured iron-iron oxide core-shell systems

Jiménez-Villacorta, F.; Prieto, C.; Huttel, Y.; Telling, N. D.; van der Laan, G.

Abstract

Experimental evidence for magnetothermal behavior in iron-iron oxide nanostructured systems has been obtained using x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at the Fe 𝐿2,3 edges. The purpose of this study is the determination of the blocked state in these spin-glass-like core-shell systems. A first overview of the magnetic species participating in the magnetic response was obtained by analyzing the XMCD at saturating fields. Also, the XAS revealed the existence of an antiferromagnetic FeO phase, likely located at the interface regions. Finally, measurements were performed at low temperature and intermediate field, where a frozen state below the blocking energy is observed. The results show that the oxide phase spins are oriented at low temperature, while the magnetic spins of the metallic core do not contribute to the XMCD, suggesting that the blocking process mainly involves the magnetic particle superspins rather than the oxide coverage phase.

Citation

Jiménez-Villacorta, F., Prieto, C., Huttel, Y., Telling, N. D., & van der Laan, G. (2011). X-ray magnetic circular dichroism study of the blocking process in nanostructured iron-iron oxide core-shell systems. Physical review B: Condensed matter and materials physics, 84(17), https://doi.org/10.1103/physrevb.84.172404

• Journal Article Type: Article
• Online Publication Date: Nov 15, 2011
• Publication Date: Nov 15, 2011
• Deposit Date: May 22, 2024
• Journal: Physical Review B
• Print ISSN: 1098-0121
• Electronic ISSN: 1550-235X
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 84
• Issue: 17
• DOI: https://doi.org/10.1103/physrevb.84.172404
• Public URL: https://keele-repository.worktribe.com/output/831341