Magnetoelastic coupling and epitaxial misfit stress in ultrathin Fe(100)-films on W(100)

Measurements of the magnetostrictive stress in epitaxial Fe films on W(1 0 0) reveal a sharp deviation of the magnetoelastic coupling in nmn films fro m bulk magnetostriction. Fe films thinner than 20 nm contract upon magnetiz ation in [1 0 0], whereas thicker films expand upon magnetization in [1 0 0 ]. In situ stress measurements are analyzed to correlate the film thickness dependent magnetoelastic coupling with the thickness dependence of film st rain. A strain dependent contribution to the magnetoelastic coupling is fou nd to describe the experimental data for films thicker than 15 nm. (C) 1999 Elsevier Science B.V. All rights reserved.