Surface preparation and characterization of single crystalline β-FeSi2

Well-defined clean surfaces of single crystalline β-FeSi2 have for the first time been prepared and characterized at the atomic scale. Surface oxide was removed by heating the crystal at 850 °C in ultra-high vacuum (UHV), resulted in an atomically flat, clean surface. Scanning tunneling microscope (STM) and low-energy electron diffraction (LEED) measurements reveal the absence of long-range surface reconstruction in the low-index (1 0 0), (1 0 1) and (1 1 0) surfaces, which is unique among compound semiconductors. However, a significant number of surface defects could still be found within the clean surface. Characterizing and controlling of those surface defects will be necessary in order to use this material in applications.