Mobile Cylindrical Magnetic Domains in Epitaxial Garnet Films

Abstract

The properties of cylindrical domains in wafers of bulk single crystals of various magnetic oxides have been extensively studied and described in recent months. Mobile cylindrical domains have been produced in single‐crystal thin films of gallium‐substituted yttrium iron garnet. The deposits are formed by chemical vapor deposition onto nonmagnetic garnet substrates greater than 1 cm² in area. A model of magnetic anisotropy in epitaxial films is proposed and shown to be in good agreement with experimental domain observations. In a typical sample, a domain diameter of 8 μ is observed in a 6‐μ‐thick film at a bias field of 25 Oe. From the domain translational velocity of 5600 cm/sec, a cylindrical domain mobility of 1500 cm/sec Oe has been calculated. A fractional change in cylindrical domain diameter of −0.07%/°K has been measured at 300°K. Annealing at 1570°K for several hours did not alter the Néel temperature or the optical transmission spectrum.