Quantitative study of magnetization ripple in Co61B39 amorphous thin films

A quantitative, two-dimensional, image processing analysis of magnetization ripple was performed. The measured longitudinal and transverse ripple wavelengths of Co₆₁B₃₉ amorphous thin films were in the range 0.6-0.7 mu m and >or=1.9 mu m respectively, and remained constant for heating below the Curie temperature T_c approximately= 350 degrees C. The measured value of the longitudinal ripple wavelength agreed well with the value calculated from Hoffmann´s ripple theory, but the transverse ripple wavelength is nearly ten times larger than expected. The ripple angle calculated from image processed data is approximately=0.2-0.3 radian and a constant for temperatures below T_c. Digital image-processing techniques have also been used to analyze thermally induced changes in the magnetization ripple of these thin films. The intensity of the magnetization ripple decreased monotonically with increasing temperature and vanished at T_c. Intense ripple was observed in films cooled from the approximately=450 degrees C crystallization temperature, T_x, and ripple width was observed to vary inversely with cutoff in the angle of incidence of the deposition beam. The significance of these observations relative to previously observed anisotropy-nanostructural relationships in these films is also discussed.