Annihilation of vertical-Bloch-line chains in the walls of the second kind of dumbbell domains subjected to an in-plane field

Abstract

An experiment was statistically performed on the annihilation of vertical-Bloch-line (VBL) chains in the walls of the second kind of dumbbell domains (IIDs) subjected to an in-plane field Hip. It was again confirmed that there is a critical in-plane field H'ip, above which all VBL chains of hard domains in garnet bubble films, including IIDs, disappear. Just like ordinary hard bubbles (OHBs), it was also found that there exists a critical range of Hip, from (Hip)ID to H'ip, for IID softening. Over this range, with the increase of Hip, more and more IIDs are softened, accompanied by the successive appearance of the first kind of dumbbell domains, OHBs and soft bubbles. In addition, for the five samples tested, the ratio, H'ip/(Hip)ID, is obviously greater than √2.