Switching Phase Diagram of Two Frequencies MAMR for ECC Media

摘要

A two-particle model is utilized to study the switching phase diagram of ECC media in the microwave-assisted magnetic recording, by applying an in-plane AC magnetic field for microwave and a DC magnetic field for write head field. An interesting result is found that, by introducing two mixed linearly polarized AC fields when the ratio of frequencies ${rm f}_{2}/{rm f}_{1}$ is in a certain range, the minimum switching DC field can be almost zero when $H_{rm ac}$ is 20% of $H_{{rm k}1}$ of hard magnetic layer. This phase diagram is also checked by a 3D micromagnetic model of ECC media with polycrystalline structure included; with two linearly polarized $H_{rm ac}$ applied, the coercivity $H_{rm c}$ can be reduced to almost zero when $H_{rm ac}=0.2 H_{{rm k}1}$, and $H_{rm c}$ still decreases from 10.5 kOe to 7.7 kOe when $H_{rm ac}=0.02 {rm H}_{{rm k}1}$.