Thin single layer materials for device application

Thermally evaporated permalloy (Ni81Fe19)and Co95Fe5 magnetic films and copper, gold, silver and aluminium non-magnetic films in the sub-15nm range have been analysed. Silicon, glass, GaAs and MgO were all investigated as substrates. Surface roughness was determined using atomic force microscopy, while magnetic characterisation of coercivity and anisotropy field was performed by a magneto-optical Kerr effect system. Clear variation in coercivity and anisotropy is seen dependent on the substrate and film thickness. Significantly, in the permalloy system, the change in magnetic and structural properties with increasing film thickness depends strongly on the substrate used: for films deposited on glass, roughness increases with increasing film thickness whereas for films deposited on silicon, roughness remains largely unchanged with increasing film thickness.