Oxygen-functionalized MXene, M2CO2 (M =group III-V metals), are two-dimensional (2D) materials with the immense possibility for device applications. Using first-principles calculations, we perform a study on the stability of M2CO2 MXenes. Depending on the position of O atoms, the M2CO2 can exist in two different phases. CB phase, where O at the top of carbon and metal atom. On the other side, O atom can occupy either the site on the top of the metal atom (BB' phase). We found that for M = Sc and Y the CB phase is stable, whereas for M = Ti, Zr, Hf, V, Nb, and Ta the stable phase is BB'. The electron localization function and atom-projected density of states, provide a rational explanation for the relative stability. Instability of BB'- M2CO2 (M = Sc and Y) originates from the weakening of M-C interactions due to the motion of C atom in the-b plane. The insight into the stability of these competing structural phases of M2CO2 is an important step in the direction of identifying the stable phases of these 2D materials and their applications.UGC-JRF/SRF fellowship.
APS March Meeting Abstracts
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