Spacer Thickness and Temperature Dependences of the Interlayer Exchange Coupling in a Co/Pt/Co Three-Layer Structure

Domain wall mobility as a function of nonmagnetic interlayer thickness and temperature was studied in ultrathin exchange-coupled ferromagnetic layers using magneto-optic Kerr microscopy. The system under study is Pt/Co/Pt/Co/Pt heterostructure having perpendicular magnetic anisotropy middle Pt layer with spatially variable thickness. interaction between the Co observed when varies from 5 to 6 nm range 200–300 K. There certain interval where domain walls both move independently. Nonlinear dependence displacement on applied field measured. It shown that an equilibrium position relaxed depends field, temperature, This determined by energy balance: (i) provided (ii) exchange area swept wall, (iii) coercivity. mechanism stabilization terms independent motion near critical considered. found coercivity decrease at higher while constant J changed weakly.