Tailoring the interfacial exchange coupling of perpendicularly magnetized Co/L10-Mn1.5Ga bilayers. (18th May 2016)

• Record Type: Journal Article
• Authors: Xiao, J X; Lu, J; Liu, W Q; Zhang, Y W; Wang, H L; Zhu, L J; Deng, H X; Wei, D H; Xu, Y B; Zhao, J H
• Is Part Of: Journal of physics. Volume 49:Number 24(2016)
• Publication Date: 2016-05-18
• Subjects: exchange interactions -- magnetic anisotropy -- spintronics -- molecular-beam epitaxy; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/24/245003
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: We have studied the magnetic properties of Co (2–12 MLs)/ L 10 -Mn1.5 Ga (15 nm) bilayers without and with annealing at 300 °C by a combination of superconducting quantum interference device (SQUID) magnetometry and x-ray magnetic circular dichroism (XMCD). We find that the Co layer can remain perpendicularly magnetized when its thickness is less than six monolayers due to the coupling between Co and L 10 -Mn1.5 Ga layers, which is doubly confirmed by both SQUID and XMCD measurements. Such an exchange coupling between L 10 -Mn1.5 Ga and Co layers changes from ferromagnetic coupling to antiferromagnetic coupling after the annealing process. Furthermore, the magnetic coupling can also be tailored from ferromagnetic to antiferromagnetic by changing the L 10 -Mn1.5 Ga surface from Mn-rich to Ga-rich. The first-principles calculations show that the interfacial coupling type is ferromagnetic for a Mn-terminated L 10 -Mn1.5 Ga bilayer, while antiferromagnetic for a Ga-terminated bilayer. The spin and orbital moments of Co in the Co/ L 10 -Mn1.5 Ga bilayers are calculated according to the sum rules and the ratio of the orbital to spin magnetic moments for Co is not enhanced like other perpendicularly magnetized Co-based multilayers such as Co/Pd and Co/Pt.