DOMAIN WALL PINNING IN AMORPHOUS TbFeCo FILMS ON PATTERNED SUBSTRATES

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.

MAGNETIC DOMAIN PINNING IN PATTERNED DyFeCo FOR THE APPLICATION OF MAGNETO-OPTICAL RECORDING

“…When the applied magnetic field was swept to reverse the magnetization, we found that the coerclvity was higher within the hole region when compared \vith that outside the hole area [4,11] ; for instance, for the square holes domain wall motion coercivity outside the hole area for sampleDY273(Fe 8o C0 2o )n 7 is 2.7 kOe, while inside the hole area, the coercivity is 3.9 kOe. It seems that the magnitude of the coercivity of the hole arrays also depends on the hole geometry.…”

“…Consequently, a written domain with fixed shape and free from jaggedness could help reduce the media noise. On~ vvay to achieve this goal is by patterning of the disk substrates as was originally proposed in [4]. In this paper, we present a novel method for pinning the magnetic domains within definite holes as MO recording marks.…”

Thermomagnetic recording in amorphous TbFeCo films on patterned substrates

“…Another possible source of the difference is the different nucleation/ wall motion coercivities of the TbFeCo film on the etched and unetched regions of the substrates [3]. Figure 4 shows results of thermomagnetic recording on patterned samples.…”

“…l(a) are obtained using the same procedure but the exposed photoresist was underdeveloped. Figure l(b) shows the raised patches obtained by the method described in [3] when the exposed photoresist was overdeveloped.…”

“…Square 1x1 pm2 patches, having a height (or depth) of 10 or 20 run, were produced by argon etching through a photoresist mask [1,3]. The result of this etching is shown in the atomic force micrographs of Fig.…”