Magnetic anisotropy and the temperature dependent magnetic order-disorder transition in Fe/Cu(001)

The temperature-driven structural transformation from f.c.t. to f.c.c. at a bout 4 ML Fe/Cu(001) was studied in detail by means of ferromagnetic resona nce (FMR) in UHV. From the temperature dependence of the FMR intensity and magnetic anisotropy energy we conclude that the structural transformation o ccurs over the full layer thickness tin the form of domains) and is not lim ited to a surface layer. Ferromagnetic f.c.t. domains decrease in volume as a function of increasing temperature and are completely transformed to f.c .c. Fe above T* approximate to 320 K. The second- and fourth-order magnetic anisotropy constants at room temperature are determined also for 2.5 ML (f .c.t.) to 30 ML (b.c.c.) Fe/Cu(001). For all thicknesses the [100] in-plane axis is favored by the fourth-order anisotropy.