Study of thermally activated reaction between Mn and GaAs(111) surface

We investigate the chemical reactivity of ultra-thin films of Mn on As-terminated (111) GaAs surface kept at ultra-high vacuum conditions in the temperature interval ranging from room temperature to 400 °C. The experiments were performed using a customized molecular beam epitaxy system equipped with reflection high energy electron diffraction and X-ray photoelectron spectroscopy techniques. These analyses were complemented with X-ray diffraction measurements to put in evidence the formation of intermediate compounds. Only Ga_1−xMn_xAs and sub-arsenised MnAs_x compounds are possibly formed below 200 °C. The onset of the reactivity occurs around 200 °C when ordered compounds such as MnAs and MnGa are observed. The formation of compounds more rich in Mn like Mn₃Ga and Mn₂As is found for deposition temperatures of 300 and 400 °C. - Highlights: • Surface chemistry of Mn in contact with GaAs surface • Formation of Mn-based compounds • Solid state reactions of Mn on GaAs