Evidence of local moment formation in Co-based Heusler alloys

Telling, N. D.; Keatley, P. S.; van der Laan, G.; Hicken, R. J.; Arenholz, E.; Sakuraba, Y.; Oogane, M.; Ando, Y.; Takanashi, K.; Sakuma, A.; Miyazaki, T.

Abstract

We examine the formation of local moments in Heusler alloys of the composition
Co2MnZ (where Z=Si or Al) using the combined techniques of x-ray magnetic circular and linear dichroism. The existence of local moments in half-metallic Heusler alloys is reliant upon the band gap in the minority-spin states. By utilizing the element-specific nature of x-ray absorption techniques we are able to explore the degree of localization of moments on Co and Mn atoms. We observe a crucial difference in the localization of the Co moment when comparing
Co2MnSi (CMS) and Co2MnAl films that is consistent with the predicted larger minority-spin gap in the Co partial density of states for CMS. These results provide important evidence for the dominant role of the Co minority-spin states in realizing half-metallic ferromagnetism in this system.

Citation

Telling, N. D., Keatley, P. S., van der Laan, G., Hicken, R. J., Arenholz, E., Sakuraba, Y., …Miyazaki, T. Evidence of local moment formation in Co-based Heusler alloys. Physical review B: Condensed matter and materials physics, 78(18), https://doi.org/10.1103/physrevb.78.184438

• Journal Article Type: Article
• Online Publication Date: Nov 25, 2008
• Deposit Date: May 21, 2024
• Journal: Physical Review B
• Print ISSN: 1098-0121
• Electronic ISSN: 1550-235X
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 78
• Issue: 18
• DOI: https://doi.org/10.1103/physrevb.78.184438
• Public URL: https://keele-repository.worktribe.com/output/830770