A new TiW seed layer for SmCo5 films with perpendicular magnetic anisotropy

► TiW seed layer improves the texture of Cu under layer. ► TiW seed layer decreases the surface roughness of Cu underlayer. ► A 5 nm TiW seed layer significantly improves the perpendicular coercivity of SmCo5 film. ► Diffusion barrier and a high melting point of TiW seed layer are the physical mechanism of the improvement for SmCo5 film with perpendicular magnetic anisotropy.