Shape of bubbles

The general form of the equation of motion of an arbitrary domain wall is obtained for materials within the uniaxial anisotropy constant K≫2πM² (M is the magnetization). In the particular case of a static bubble it leads to the equilibrium equation, determining the dependence of the bubble radius R(z) on the coordinate z along the film thickness. This equation does not have a solution R(z) = constant, i.e. bubbles cannot be cylindrical, but have to be bent.