アモルファスＣｏ９１Ｈｆ６Ｐｄ３／ＳｉＯ２／Ｃｏ９１Ｈｆ６Ｐｄ３積層膜の磁気特性と磁区構造

Abstract

The magnetic domain structure and the magnetization process of amorphous Co91Hf6Pd3/SiO2/amorphous Co91Hf6Pd3 multi-layered films which were photofabricated in rectangular patterns have been investigated.Exchange interaction between magnetic layers 1500 Å thick occurs when the thickness of the intermediate SiO2 layer prepared by sputtering is less than about 10 Å. When the SiO2 layer is about 10000 Å thick, however, magnetostatic interaction becomes weak and the magnetic layers become independent of each other. We have determined that when multilayered films have an SiO2 layer from 20 to 600 Å thick and are at least 10μm wide along the easy axis, no domain walls are present because magnetostatic interaction causes the magnetization of one magnetic layer to be oriented anti-parallel to that of the other along the easy axis.When a magnetic field is applied along the easy axis, the domain walls nucleate and displace only in the magnetic layer whose magnetization is anti-parallel to the field. On the other hand, when multi-layered films are subjected to a magnetic field along the hard axis, their magnetization is rotated.