Dynamic properties of bubbles and stripes in tilted [111] garnet films

Abstract

Several kinds of garnet films have been grown by LPE techniques on substrates whose surface normals slightly tilt from the crystallographic [111] axis. Magnetic anisotropies induced in these films are orthorhombic-like. With the increase of the [111] axis tilting angle Δ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> , the easy direction of a uniaxial part K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">u</inf> tilts away from the surface normal and the magnitude of an in-plane part K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> , which is not the projection of K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">u</inf> onto the film plane, increases almost linearly, reaching <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\eta\equivK_{p}/2\piM_{s}^{2}\simeq5</tex> at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\Delta_{c}\simeq6\deg</tex> . In order to investigate the effect of in-plane anisotropy thus induced on the domain wall motion, bubble and stripe domain transport velocities are measured. Both bubble and stripe velocities increase with the increase of in-plane anisotropy. However, the increase of peak velocities of stripe domains, which has been shown to correspond to the punch-through threshold of a horizontal Bloch line in a plane wall, with the increase of K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> is much smaller than that predicted by Schlömann's calculation.