Magnetism and Structure of Compositionally Modulated Fe-Gd Thin Films

Electron-beam heating was used to evaporate Fe and Gd on glass in attempts to form compositionally modulated thin films with vertical periodicity. The film structure was varied, from 300 6-Å layers to 25 250-Å layers. Small-angle X-ray diffraction confirmed the formation of compositionally modulated cycles greater than 20 Å; for smaller periodicities, the structure was amorphous. A compensation temperature of 200 K was taken to indicate that magnetic moments within Fe and Gd layers were ferromagnetic but oppositely directed.