Microwave-Field-Induced Magnetization Excitation and Magnetization Switching of an Antiferromagnetically Coupled Magnetic Bilayer with Perpendicular Magnetization

摘要

Antiferromagnetically coupled (AFC) media that consists of two antiferromagnetically coupled magnetic layers has been explored for magnetic recording [1]. Because the AFC media reduces the dipolar interaction, it improves the reliability of writing and the stability of data. In microwave-assisted magnetic recording (MAMR), which is a candidate for next-generation magnetic recording [2,3], the dipolar interaction raises other concerns. MAMR utilizes large-amplitude ferromagnetic resonance (FMR) excitation in media magnetization to assist writing, and the dipolar interaction leads to the distribution in FMR frequency and the collective magnetization excitation in multiple grains. In this respect, AFC media is considered to be advantageous for MAMR [4,5]. In this study, we fabricate an AFC magnetic dot consisting of two Co/Pt multilayers and investigate magnetization excitation and switching in a microwave field.