Strong out-of-plane magnetic anisotropy of Fe adatoms onBi2Te3

Abstract

The electronic and magnetic properties of individual Fe atoms adsorbed on the surface of the topological insulator ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$(111) are investigated. Scanning tunneling microscopy and spectroscopy prove the existence of two distinct types of Fe species, while our first-principles calculations assign them to Fe adatoms in the hcp and fcc hollow sites. The combination of x-ray magnetic circular dichroism measurements and angular dependent magnetization curves reveals out-of-plane anisotropies for both species with anisotropy constants of ${K}_{\text{fcc}}=(10\ifmmode\pm\else\textpm\fi{}4)$ meV/atom and ${K}_{\text{hcp}}=(8\ifmmode\pm\else\textpm\fi{}4)$ meV/atom. These values are well in line with the results of calculations.