The 210th Special MMU seminar   


Media material characterization by Ferromagnetic resonance with cavity method

Prof. Shin Saito
Department of Electronic Engineering, Graduate School of Engineering, Tohoku University

Date & Time: 15:30 - 16:30, October 30th (Fri), 2015.
Place: 7F Small Seminar Room, Sengen

Abstract:

  Magnetic moments in domains corresponding to specific magnetized state in hard disk media precess under the influence of various intrinsic- and interaction-magnetic fields. The total effective field Heff consists of anisotropy field (Hk), dipole interaction field, self-demagnetizing field and exchange coupling field Hex. Ferromagnetic resonance (FMR) is well-known as a method to evaluate Heff quantitatively through precession dynamics. Therefore, we applied FMR with the cavity technique to currently used stacked media (CoPt-based alloy capping layer/ CoPt based alloy-Oxide granular layer) and evaluated I) Hk and g-factor, II) the interlayer- and intergranular- Hex and III) effective damping factor. In the presentation, we will discuss about broadening FMR signal phenomenon due to distribution of Heff and/or transition from acoustical to optical mode.