Manipulation of spin reorientation transition of ultrathin Co films by using an artificially roughened Pd(111) substrate

Abstract

The authors present a simple method to control the spin reorientation transition (SRT) in ultrathin Co films using an artificially roughened substrate prepared by ion bombardment with varying the incident angle phi from 0 degrees to 80 degrees. The combined study of surface magneto-optical Kerr effects and scanning tunneling microscopy revealed a drastic increase of the onset thickness of the SRT (t(c)) by up to 41% for the substrate sputtered at phi=80 degrees, whereas there is an 18% reduction for the phi=20 degrees sample relative to the SRT in the smooth surface. The second- and fourth-order surface anisotropies (K-2s and K-4s) responsible for the drastic change in the SRT are determined from a theoretical fit to the magnetization orientation in the spin reorientation region. (c) 2007 American Institute of Physics.