Depresión perimenopáusica: una revisión

Abstract

We report a comparative study of the synthesis and the structural and electronic properties of hexagonal boron nitride (h-BN) and graphene layers grown on the Ir(111) surface. By performing photoemission (PE) experiments time-dependently and supplementing them by low-energy electron diffraction (LEED) data, we demonstrate the differences and similarities of their formation, and we show the temperature regimes which allow these materials to be created with high crystalline quality. It has been demonstrated that synthesis at low temperatures leads to the formation of disordered domains of h-BN as well as graphene flakes on the metallic surface. The LEED patterns of such samples reveal a complex structure which indeed can be easily interpreted by using the model presented here. The angle-resolved PE study of h-BN/Ir(111) demonstrates the presence of replicated electronic states, which are quite similar to those detected and widely discussed for the graphene/Ir(111) system. On the basis of these results and the corresponding model calculations, we argue that the appearance of these replicated bands is mainly caused by the geometrical corrugation of the system.