Evaluation of Magnetic Perpendicular Anisotropy of Vapor Quenched Fe Films Using Mössbauer Effect

Pure Fe films were produced by rf sputtering under several Ar gas pressures and were investigated with an SEM and Mössbauer effect. In the Mössbauer spectra, a perpendicular magnetic anisotropy was observed for films made under high Ar gas pressures, while an in-plane anisotropy was seen for films made under low Ar gas pressures. The anisotropy of the films did not change after one hour of annealing at 300 K. Films made under low Ar gas pressures have a fine fiber structure, while films made under high Ar gas pressures have a columnar structure separated by distinct boundaries. Assuming that the magnetic interaction within the columnar structure is weak, the perpendicular magnetic anisotropy of the films under high Ar gas pressures can be explained by the shape anisotropy of the columnar structure.