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

Abstract

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.

SHORT RANGE ORDER IN ANNEALED FexSi1-x AMORPHOUS FILMS

“…Their results are also plotted in figure 1. In other works concerning sputtered thin films [2] [6], this plateau was not so marked. Finally, in thick (1-2 p) vacuum evaporated [7] (see Fig.…”

“…Magnetic moment p and spin wave stiffness D are almost enterely determined by chemical disorder [I], while structural disorder also plays for local anisotropies [2]. In FeSi compounds.…”

“…In fig&e 1 SK VS. 2 for as-prepared and annealed films is shown. SK = AR/R is the Transverse Kerr effect phenomenological parameter, where R is the reflectivity and AR the magneto-optical modulation [4].…”

MICROMAGNETIC PROPERTIES OF AMORPHOUS CoxY1-x SPUTTERED FILMS WITH Mo OVERLAYERS

“…Scanning Auger deep-profiles analysis, now in progress, seems to confirm these hypothesis. Otherwise, in reference [I] we suggest that magnetization ripple deduced from TBIS measurements for films where x > 0.70, may arise, not only from the intrinsic contribution of randomly distributed local anisotropies inherent to amorphous alloys [6], but an additional contribution from magnetic inhomogeneities localized in the film-air interface could be expected. To elucidate this point, TBIS measurements were carried out in Coo.soY0.20 films protected with Mo overlayers.…”

“…For film thickness lower than 100 A, perpendicular anisotropy effects on the macroscopic magnetic behaviour (stripe domains) [6], makes ripple characterization from TBIS measurements ambigous. This is the main reason of the observed scatter in S values.…”