No abstract

AIIstrad • Magnetization reversal in amorphous TbFeCo films on patterned glass substrates was studied. Two types of patterns were examined: grooves and square patches. Pinning of the domain walls at the side-walls of the patterns was observed. The pinning depends on the depth of the patterns and the angle of the side-walls: greater depth and steeper side-wall produce stronger pinning.Thennomagnetic recording experiments confirm the ability of patterned substrates to confine recorded domains within boundaries defined by the side-walls.

The present work deals with DW dynamics in amorphous films with perpendicular Tbx(Fea5c0i5) Loo-x magnetic anisotropy. The Tb content of the films varied from 18 to 28 at.% . The character of DW motion was observed to depend significantly on the resultant film magnetization, amplitude of pulse magnetic field and on Tb content. The DW mobility was shown to be an asymmetric function with respect to the compensation composition. Critical velocities in the films have not been registered.

A method with high spatial resolution is developed to study wall motion in thin magnetic films with perpendicular anisotropy. Barkhausen jumps during domain wall motion in amorphous TbFeCo films and polycrystalline Co/Pd multilayer films have been observed. The average distance between strong pinning sites in Co/Pd was found to be around 0.3–0.4 μm. Maximum pinning times as long as several seconds were observed. Magnitudes of major jumps in TbFeCo were around 0.7 μm.