Magnetic bubbles in Ni1−xAux alloys

Abstract
Lorentz electron microscopy and small angle electron diffraction techniques as well as Kerr effect and magnetization measurements have been carried out on a series of Ni 1−x Au x thin films with 0?x?0.20. These films consist of a Ni‐Au fcc solid solution. The films showed a preferred orientation with a 〈111〉 axis normal to the film plane. Films with x=0 and 0.20 showed typical thin film Bloch wall ripple domain structures. Films with x=0.05, 0.10 and 0.15 showed ’’weak’’ stripe domain patterns zero field ranging from paralle zero field ranging from parallel aligned domain walls at x=0.05 to an almost random or ’’wickerwork’’ type structure at x=0.15. An applied field caused the weak stripe contrast to increase until at ∠2 kOe, bubble domains could be nucleated. The bubbles existed predominantly in the 0 Bloch line state with both chiralities present. A few bubbles with 2 Bloch lines were also noted. In all cases the diameter of the bubbles was approximately 800 Å.