Expanding the Structural and Compositional Space of Two-Dimensional M₂X₂T_y Materials via Simulated Etching of Layered YM₂X₂ Phases

High Resolution Image Download MS PowerPoint Slide Inspired by the recent synthesis of 2D Ru 2 Si x O y, obtained by selective removal of Y from the 3D parent phase YRu 2 Si 2, we simulate the selective etching process of the family of laminates YM 2 X 2, with M being a 3d, 4d, or 5d transition metal and X = Al, Ga, In, Si, Ge, Sn, P, As, Sb, S, Se, or Te. We assess the thermodynamic stability of 300 3D YM 2 X 2 compounds through the formation enthalpy with respect to competing phases, Δ H cp, where Δ H cp < 0(20) meV/atom predicts a phase as thermodynamically stable (close to stable). 3D phases predicted as stable are assessed computationally for selective etching of Y in acidic media, resulting in ideal 2D units M 2 X 2 T y, where O and F are considered as terminating species T. We predict 17 2D structures, out of which 11 are not previously reported. All of these are identified as dynamically stable and are predicted to be possible to synthesize through selective etching of parent 3D compounds. All are found to be either metals or semimetals, with further tuning potential being possible by alteration of surface terminations.