Abstract
Epitaxial DySi 2-x films were grown in a-Si (15 nm)/Dy (30 nm)/(111)Si samples annealed at 700°C for 10 min in an ultrahigh vacuum chamber. From the electron diffraction pattern analysis, the structure of the epitaxial DySi 2-x thin films were determined to consist of a superstructure of an √3 × √3 R 30° vacancy ordering structure with an out-of-step structure. The three-dimensional structure of the √3 × √3 R 30° vacancy ordering was determined to be (√3 × √3 R 30° 2c). The periodicity along the c-axis of the out-of-step vacancy ordering structure with M = 2 was also analyzed to be 2c. The intrinsic structure was found to transform to various modulated structures by ion bombardment during cross-sectional transmission electron microscope (TEM) sample preparation.