Shape anisotropy induced modification of the magnetization reversal processes in epitaxial microstripes

The magnetization reversal processes of a 150 A thick epitaxial Fe/GaAs(001 ) film are modified by controlling the lateral dimensions of the continuous film to create rectangular microstripes of constant length and varying wid th. Size dependent transitions from (a) two-jump to single-jump, and (b) si ngle-jump to two-jump reversal processes are observed for magnetization rev ersal along the two mutually perpendicular cubic easy axes (parallel and pe rpendicular to the easy axis of the shape anisotropy, respectively). This b ehavior can be explained by a simple model of the effective anisotropy ener gy contributions including the shape anisotropy energy. (C) 2000 American I nstitute of Physics. [S0021-8979(00)03309-0].