Effects of in-plane magnetic field on bubble properties in ion-implanted garnet fims

Abstract

In the ion-implanted garnet films for hard bubble suppression, there exist planar closure domains associated with bubbles, which are created or annihilated by a rotating in-plane magnetic field. We have investigated the effects of closure domains on magnetic bubble properties in the epitaxial films of (YEuYbCa) 3 (FeGe) 5 - O 12 implanted with Ne+ or H+ ions. Experimental results are summarized as, (1) static coercivity in the H+ implanted film exhibited a 3-fold symmetry, as in the bubble collapse field, in response to the behavior of closure domains when the in-plane field of 40 Oe was rotated. (2) Wall state switching for decreasing in-plane field in the film implanted with 2 \times 10^{14} Ne+/cm2at 100 keV depended on the directions of the in-plane field. When the in-plane field Hp was applied in the [ 11\bar{2} ] direction with the bias field applied in the [111] direction, distinct wall state transitions occured at about Hp=120 Oe, 40 Oe and 10 Oe. When Hp was applied in the [ \bar{1}\bar{1}2 ] direction, however, wall state changed continuously below Hp=120 Oe at which distinct wall state transition occured.