Investigation of the geometric and electronic structures of ErSi(2−x) with the density functional theory and comparison with STM images

Study of ErSi(2−x) surfaces system is submitted at one controversy in reason of the STM images bias voltage dependence. In this article, we have investigated by means of calculations issued of the density functional theory (DFT), atomic surface density for 2D and 3D epitaxial erbium silicide on Si(1 1 1). DOS (density of state) in front of the surface, calculated with Wien2k, permits to simulate scanning tunneling microscopy (STM) images in function of the bias voltage and to discriminate the different surface arrangements. The calculations confirm the model of structure accepted and give some new elements in order to close the controversy on the question.