Investigation of magnetization reversal and domain structures in perpendicular synthetic antiferromagnets by first-order reversal curves and magneto-optical Kerr effect

• Published in: Chinese physics B Vol. 32; no. 11; pp. 117502 - 657
• Main Authors: Wang, Xiang-Qian, Li, Jia-Nan, He, Kai-Zhou, Xie, Ming-Ling, Zhu, Xu-Peng
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.10.2023
• Subjects: domain; first-order reversal curves; magnetization reversal process; perpendicular synthetic antiferromagnet; magnetization reversal pro-cess; first-order reversal curves; perpendicular synthetic antiferromagnet; domain
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/acd8aa

Perpendicular synthetic-antiferromagnet (p-SAF) has broad applications in spin-transfer-torque magnetic random access memory and magnetic sensors. In this study, the p-SAF films consisting of (Co/Ni) 3 ]/Ir( t Ir )/[(Ni/Co) 3 are fabricated by magnetron sputtering technology. We study the domain structure and switching field distribution in p-SAF by changing the thickness of the infrared space layer. The strongest exchange coupling field ( H ex ) is observed when the thickness of Ir layer ( t Ir ) is 0.7 nm and becoming weak according to the Ruderman–Kittel–Kasuya–Yosida-type coupling at 1.05 nm, 2.1 nm, 4.55 nm, and 4.9 nm in sequence. Furthermore, the domain switching process between the upper Co/Ni stack and the bottom Co/Ni stack is different because of the antiferromagnet coupling. Compared with ferromagnet coupling films, the antiferromagnet samples possess three irreversible reversal regions in the first-order reversal curve distribution. With t Ir increasing, these irreversible reversal regions become denser and smaller. The results from this study will help us understand the details of the magnetization reversal process in the p-SAF.