On the punch-through of Bloch loops in magnetic bubbles

Abstract

Bubble translational motion in gradient drive fields has been carefully studied for both as‐grown and ion‐implanted films of (YEuTmCa)₃(GeFe)₅O₁₂ by using the rocking method. At a critical gradient amplitude which is found to depend on the drive pulse width, the motion of a bubble in an as‐grown film becomes nonreproducible as evidenced by the fuzzy appearance of the bubble. Under the same critical amplitude drive condition, the skew angle of an S=1 bubble in an ion‐implanted film decreases abruptly. This is attributed to punch‐through of nucleated Bloch loops. The punch‐through time was measured as a function of drive, and a reasonably linear relation between the inverse punch‐through time and gradient drive field was found.