STRUCTURAL AND MAGNETIC PHASE-TRANSITIONS OF FE ON STEPPED CU(111)

The magnetism and its correlation with morphology and structure of ult rathin Fe/Cu(111) films have been studied. At room temperature, the fi lms grow in a quasi-one-dimensional form (stripes) in the submonolayer range. Between 1.4 and 1.8 ML the stripes percolate and become two-di mensional films. The remanent magnetization of the percolated films wa s observed to be significantly more stable with respect to time than t hat of tile stripes. AL low thickness (<2.3 ML) the films adopt the fe e structure from the substrate and later transform to bcc(110) structu re with Kurdjumov-Sachs orientation. Experimental evidence suggests th at the fee films have a low-spin ferromagnetic or ferrimagnetic phase, and a perpendicular easy magnetization axis. The magnetization switch es to an in-plane high-spin phase after the fee to bce structural tran sformation has been accomplished. [S0163-1829(97)02541-1].