Structure and Perpendicular Magnetic Properties of FeBi Films by Evaporation Method

We have studied the dependence of the Bi composition on the perpendicular magnetic anisotropy of thin films evaporated from Fe
_100-x
Bi
_x
evaporant at the film growth site. The films were prepared by a point-source vacuum evaporation method in which Fe and Bi were evaporated from the same source. The evaporated films clearly showed perpendicular magnetization characteristics at x = 1.6 at%. The saturation magnetization 4πM
_s
, remanent magnetization 4πM
_r
⊥ and coercive force H
_c
⊥ were 20×10
³
G, 0.6×10
³
G and 500 Oe, respectively. One cause of the increase in the magnetization is thought to be the effect of the perpendicular orientation of Fe columnar grain growth, which occurs just as the Bi reevaporates. That is, formation of regular columnar grains with excellent orientation has a favorable influence on the magnetization characteristics. We inquired into the process of the growth of films using an X-ray diffractometer, AES analysis, and SEM photographs, and determined the optimum conditions for film fabrication.