Micromagnetics of ion-implanted garnet layers

The micromagnetics of a garnet two-layer system are reviewed bearing in mind various aspects of magnetic bubble technology. Calculations of the transition wall between the uniaxial basic layer and the planar top layer are extended to include the effects of a bias field and of cubic crystal anisotropy. Platelike domains in the basic layer produce an interesting closure pattern in the top layer. The influence of the closure configuration on the equilibrium domain width is calculated. In the third section the properties of planar domains occuring in the top layer when the basic layer is saturated are studied. Using earlier charged wall calculations the wall orientation angle of zig-zag walls is calculated. Special features at edges of the implantation as e.g. strongly charged walls and so-called edge-walls are studied. Finally, comments are made on the interactions between bubbles and the top layer.