Role of bottom layer in double recording layer for antiferromagnetically coupled longitudinal media

To clarify the physical origin of high remanent coercivity (H_cr) against the ratio of double recording layers, physical magnetic quantities such as magnetic anisotropy field (H_k), inter-granular interaction (exchange coupling and static magnetic coupling), and thermal agitation were separately discussed for antiferromagnetically coupled media. The AFC media were deposited on textured NiP plated Al substrate. The stacking structure was sub/CrX (underlayer)/CoCrTa (stabilizing layer)/Ru(spacing layer)/CoCrPtB(bottom recording layer)/CoCrPtB(top recording layer).