It was noted that the phase stability and mechanical properties of Ti2AC (A = Ga,

Cd, Sn, In and Pb) had a close relationship to the behaviour of group-A element

atoms in these compounds. It was shown here that, although the Al, Ga and In (or

Si, Sn, and Pb) were in the same group, the migration energy and vacancy

formation energy of the group-A atom in Ti2GaC/Ti2InC (or Ti2SnC/Ti2PbC) were

noticeably lower than those in Ti2AlC (or Ti3SiC2). The present results were

helpful to a better understanding of the easy out-diffusion and self-extrusion of

group-A atoms in these compounds.

Theoretical Investigation of A-Element Atom Diffusion in Ti2AC (A=Sn, Ga, Cd, In,

and Pb). B.Liu, J.Y.Wang, J.Zhang, J.M.Wang, F.Z.Li, Y.C.Zhou: Applied Physics

Letters, 2009, 94[18], 181906