Unified And Ultimate High-Pressure Phase Of Several Nanolaminate M(N+1)Ax(N) (N = 1, 2, 3, Etc.) Ceramics From First Principles

We did extensive research for the nanolaminate M(n+1)AX(n) (n = 1, 2, 3, etc.) ceramics on their structural stability, in which the "M", "A" and "X" dependence of the phase transition pressure is concluded. Mo2GaC presents multi-phase co-existence status at high pressure. The hexagonal P6(3)/mmc to tetragonal P4/mmm transition is the common direct route for the N-containing MAX due probably to the high transition pressure. P6(3)/mmc (No.194, alpha, beta) alpha -> beta -> P4/mmm transition might be the common route for the C-containing MAX due probably to the low alpha -> beta transition pressure. Nb2InN/Nb2GaN and Mo2InN present c-axis abnormal elongation at low pressures.