摘要: Iron silicide (FeSi) provides multiple fascinating features whereby intriguing functional properties bearing significant application prospects were recognized. FeSi is understood notably as a correlated d -electron narrow-gap semiconductor and a putative Kondo insulator, hosting unconventional quasiparticles. Recently, metallic surface conduction channels were identified at cryogenic conditions and suggested to play a key role in the resistivity of high-quality single-crystalline specimens. Motivated by these findings, we prepared and closely examined a FeSi(110) surface with atomistically defined termination and topography. In the low-temperature regime, where surface metallicity emerges, the electronic band gap undergoes a subtle evolution. The pertaining key features, asymmetrization of the gap shape and formation of in-gap states, underscore the similarity of FeSi to unequivocal topological Kondo insulator materials. All study data are included in the article and/or supporting information.