Magnetic domain structure in ultrathin Cu/Ni/Cu/Si(001) films (invited)

Abstract

We present a series of magnetic force microscope (MFM) images of epitaxial magnetic thin films. The films studied, Ni/Cu/Si(001) capped by 2 nm of Cu, exhibit perpendicular anisotropy over an exceptionally broad thickness range, 2 nm<h<14 nm. The magnetic domain structure of the as-grown films shows a sharp transition to a finer length scale above a finite critical thickness of 12 nm. Micromagnetic theory provides the first quantitative description for these general but previously unexplained phenomena. Further we discuss MFM data obtained on films with a thickness larger than 14 nm. These films show a pronounced in-plane anisotropy.