Barium ferrite (BaM) is considered to be an excellent candidate for magnetic recording medium because of its high anisotropy field, mechanical hardness, and chemical stability. It is especially advantageous for the near contact mode magnetic recording without any over coating. But the BaM films with c-axis perpendicular orientation possess a relatively low H{sub}(C⊥) that may be attributed to a magnetic coupling between the grains and a formation of multi-domain structures due to the grain growth. To minimize this problem one of the remedies is to prepare magnetic grains isolated by the non-magnetic material. In our previous study, it has been found that, Al underlayer can improve the crystallographic property of BaM thin film remarkably and hence reduces the crystallization temperature to near about 600℃ by flash annealing process. Whereas BaM thin film deposited on the Si (111) substrate was amorphous at the same annealing temperature. Al and Si are immiscible into each other, therefore Al and Si will remain separately in an Al-Si films. If BaM deposited on this Al-Si layer, it is expected that the BaM grains deposited on the Al part can be crystallized and surrounded by the amorphous BaM matrix deposited on Si part.
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