Abstract
Epitaxial growth of Ni thin films on GaAs(001) and their magnetic property have been investigated using reflection high energy electron diffraction and magneto-optical Kerr effect. The result shows that a body-centered-cubic (BCC) phase of Ni which does not exist in nature can grow epitaxially up to 2.5 nm on the GaAs(001) substrate, and it is determined to be ferromagnetic showing a four-fold in-plane magnetic anisotropy with the easy axes along the < 100 > directions.