Manipulating the mechanical properties of Ti2C MXene: Effect of substitutional doping

With the aim of manipulating the mechanical properties of the recently discussed two-dimensional material MXene, we investigate the effect of alloying. We consider substitutional doping of B and V at Ti and C sites of ${\mathrm{Ti}}_{2}\mathrm{C}$. Calculations of quantities such as in-plane stiffness, Young's modulus, and critical strain through rigorous first-principles technique establish that B doping is highly effective in improving the elastic properties. Oxygen passivation of B-doped ${\mathrm{Ti}}_{2}\mathrm{C}$ in addition to improved elastic properties also exhibits reasonably high critical strains making them ideally suited for applications in flexible devices. Our study further reveals the presence of strong spin-phonon coupling in unpassivated ${\mathrm{Ti}}_{2}\mathrm{C}$ compounds which influences the mechanical behavior. The damage of ${\mathrm{Ti}}_{2}\mathrm{C}$ in its magnetic ground state of A-type antiferromagnetic structure is found to occur at much higher strain than that of the nonmagnetic ${\mathrm{Ti}}_{2}\mathrm{C}$.