MAGNETIC DOMAIN DYNAMICS IN FeTb THIN FILMS

Magnetic domain patterns and their dynamics in 500 Å thick Fe1_xTbx amorphous magnetron-sputtered films with 0.16 < x < 0.35 have been studied experimentally. All films possess a strong perpendicular anisotropy (PMA) with the anisotropy constant KU ≈ 3·106 erg/cm3 . For the observation of the magnetic domains a Kerr microscopic technique was used. The Kerrmicroscopical observations showed that the domain patterns are strongly dependent on the film composition. It was also seen that the deviation of the composition from the compensation point (x ≈ 0.23) plays a decisive role in the pattern appearance. The time dependence of the integral Kerr amplitude gives the temporal evolution of the remagnetization process. In order to describe the experimental observations a micromagnetic model was developed showing good agreement with the experimental results.