Ion beam sputter deposited Permalloy thin films

Ni₈₀Fe₂₀ thin films were deposited using a wide range of process parameters in a dual source ion beam sputter deposition system. The films were characterized structurally, chemically, and magnetically. Two modes of deposition were investigated; the first permitted concurrent second source bombardment during film deposition but was limited in net deposition rate to about 300 Å/m; the second provided deposition rates in excess of 1000 Å/m, but did not allow for concurrent ion bombardment from the second ion source. Depending on specific conditions film stress varied from slightly tensile to highly compressive in both deposition modes. This, combined with small variations in magnetostriction, resulted in films with vertical anisotropy and stripe domain patterns as well as conditions where well-formed closure domain patterns were observed in yoke shaped structures. For monolithic films, easy axis coercivities <0.7 Oe, anisotropy fields ≃5Oe and hard axis coercivities of <0.5 Oe were obtained