Domain-wall dynamics in garnet films with orthorhombic anisotropy

Abstract

The dynamics of domain walls in (110) oriented manganese containing garnet films have been studied. Bubble films and special films in which a single straight domain wall can be stabilized have been prepared. The magnetic anisotropy in these films is orthorhombic and the influence of the in-plane anisotropy field on the maximum domain-wall velocity has been studied. The observed maximum velocities, varying between 40 and 1500 m s−1, are usually considerably lower than the maximum velocities predicted by theory. However, for very high in-plane anisotropy fields the experimental maximum velocities approximate the theoretical ones. From the comparison of different samples it has been concluded that the maximum velocity of the bubbles having no Bloch lines is not very different from the maximum velocity of straight domain walls. Furthermore, it has been shown that the maximum velocity is independent of the film thickness. The influence of external in-plane fields on the maximum velocity also has been studied. In-plane fields in the hard direction of magnetization have no influence on the maximum velocity. In-plane fields small compared with the in-plane anisotropy field increase the maximum velocity considerably if these in-plane fields are applied in the direction perpendicular to the hard axis of magnetization. The influence of stray fields on the maximum velocity is discussed.