Fabrication and Magnetic Properties of Fe Thin Films on a Substrate Excited by SAW

Fe films of thickness 300Å were prepared by electron beam evaporation and dc magnetron sputtering onto LiNbO
3
single-crystal substrate excited by surface acoustic waves (SAWs) at 45 MHz. A biaxial anisotropy was induced in the film plane for evaporated films with the substrate excited at 8 V, but was not induced at all in sputtered films. The saturation magnetization M
s
of the evaporated films increased with increasing excitation voltage, and reached the bulk value at an excitation voltage of 8 V. However, the M
s
of sputtered films was not changed by SAW excitation. The density of evaporated films was close to the density of bulk Fe at an excitation voltage of 8 V. This fact shows that the structure of evaporated films changed from a porous to a dense structure with SAW excitation. Further, the film surface became smooth when the substrate was excited.