Magnetic Properties of Amorphous FexSi1−xFilms. I. Transverse Susceptibility, Structure Constant, and Local Anisotropy

Transverse biased initial susceptibility measurements are performed in sputtered FexSi1−x films (0.85 ≧ x > 0.60; thickness: 30 to 300 nm). Both χt(0) and χt(π/2) are measured. The deduced structure constant S in amorphous FexSi1−x; thin films (0.75 ≧ x > 0.60 and thickness in the range 30 to 100 nm) is S = 6 × 10−5 J/m2. The physical origins of the related local anisotropies are discussed in terms of the random anisotropy model of amorphous magnetism. From 8, values of local anisotropy: 105 J/m3 < Kloc ≦ 106 J/m3 related with correlation lengths: 2 nm > d ≧ ≧ 0.25 nm are deduced.