May 17, 2024

Vahid Fallahi

Academic rank: Associate professor
Address: Department of Photonics, University of Bonab, Bonab 5551761167, Iran
Education: Ph.D in Photonics
Phone: 04137745000 - 1641
Faculty: Faculty of Science
Department: Photonics

Research

Title
Depth-Dependent Magnetization Profiles of Hybrid Exchange Springs
Type Article
Keywords
Researchers Thi Ngoc Anh Nguyen، Ronny Knut، Vahid Fallahi، Sunjea Chung، Quang Tuan Le، Seyed Majid Mohseni Armaki، Olof Karis، Sergey Peredkov، Randy Kenneth Dumas، Casey W. Miller، Johan Åkerman

Abstract

We report on the magnetization depth profile of a hybrid exchange-spring system in which a Co=Pd multilayer with perpendicular anisotropy is coupled to a CoFeB thin film with in-plane anisotropy. The competition between these two orthogonal anisotropies promotes a strong depth dependence of the magnetization orientation. The angle of the magnetization vector is sensitive both to the strength of the individual anisotropies and to the local exchange constant and is thus tunable by changing the thickness of the CoFeB layer and by substituting Ni for Pd in one layer of the Co=Pd stack. The resulting magnetic depth profiles are directly probed by element-specific x-ray magnetic circular dichroism of the Fe and Ni layers located at different average depths. The experimental results are corroborated by micromagnetic simulations.