Magnetic properties of SmCo/Cr thin films with Cr under different preparation conditions

We have investigated the magnetic properties of SmCo/Cr thin films with Cr underlayer prepared at different Ar pressures by dc magnetron sputtering. All samples have in-plane anisotropy. The magnetic property studies indicate that the coercivity at room temperature of SmCo/Cr thin film is up to 4.20 kOe when prepared at higher Ar pressure (0.40 Pa), and 1.60 kOe when prepared at lower Ar pressure (0.08 Pa). The shapes of initial loop for two conditions suggest that wall pinning is the dominant coercivity mechanism. Shapes of remanence curves indicate that the films prepared at higher Ar pressure have both positive and negative exchange coupling, and the films prepared at lower pressure have only negative exchange coupling.