R&D: MAMR Writability and Signal-Recording Characteristics on Granular Exchange-Coupled Composite Media

Journal of Magnetism and Magnetic Materials has published an article written by T.Tanaka, K.Kurihara, Department of Electronics, Graduate School of Information Science and Electrical Engineering, Kyushu University, Motoota 744, Nishi-ku, Fukuoka 819-0395, Japan, X.Ya, Institute of Mathematics for Industry, Kyushu University, Motoota 744, Nishi-ku, Fukuoka 819-0395, Japan, Y.Kanai, Department of Information and Electronics Engineering, Niigata Institute of Technology, Fujihashi 1719, Kashiwazaki, Niigata, 945-1195, Japan, X.Bai, Amazon.com Services LLC, East Palo Alto, CA, 94303, United States, and K.Matsuyama, Department of Electronics, Graduate School of Information Science and Electrical Engineering, Kyushu University, Motoota 744, Nishi-ku, Fukuoka 819-0395, Japan.

Abstract: “Exchange-coupled composite (ECC) media present a possible layered structure for microwave-assisted magnetic recording (MAMR) systems. In this paper, MAMR writability and read/write characteristics were computed using a micromagnetic simulation, which assumed ECC media with graded and notched anisotropy structures. Writability was estimated from the switchable maximum averaged anisotropy field for footprint images. The calculation indicated 40% to 50% enhanced writability by microwave assistance for both graded and notched anisotropy structure media with suitable magnetic parameters. A read/write simulation indicated that notched-structure media with strongly coupled magnetic layers tended to be advantageous for signal-to-noise ratio and indicated well-confined recorded bits with a narrow magnetic write width.“