Experimental evidence of domain wall assisted switching in composite media

We fabricated perpendicular media with decoupled magnetic grains that consist of a low magnetocrystalline anisotropy layer with various thicknesses directly grown on top of a high anisotropy layer. Nonuniform magnetization rotation was confirmed by measuring coercivity and remanent coercivity in these media. The reduction of remanent coercivity with increasing the low anisotropy layer thickness, measured at low temperature, is consistent with micromagnetic calculations. These results suggest domain wall assisted switching in composite media.