Thickness-Dependent Magnetic Properties of Ni81Fe19, Co90Fe10 and Ni65Fe15Co20 Thin Films

We present results of magnetization and magnetic anisotropy in thin magnetic films of the alloys Ni₈₁Fe₁₉,Co₉₀Fe₁₀ and Ni₆₅Fe₁₅Co₂₀ that are commonly used in magnetoelectronic devices. The films were sandwiched between layers of Ta. At room temperature the critical thickness for all the films to become ferromagnetic is in the range of 11 to 13 ° A. In Co₉₀Fe₁₀ the coercivity and the anisotropy field both depend strongly on layer thickness.