New phases’ discovery in MAX family

Abstract Present work reviewed the discovery of new MAX phases since 2004. To date, there were new compounds synthesized in the Ti–Si–C (Ti 4 SiC 3 , Ti 5 Si 2 C 3 and Ti 7 Si 2 C 5 ), Ti–Al–C (Ti 5 Al 2 C 3 ), Ti–Ge–C (Ti 4 GeC 3 , Ti 5 Ge 2 C 3 and Ti 7 Ge 2 C 5 ), Ti–Sn–C (Ti 3 SnC 2 ), Ti–Ga–C (Ti 4 GaC 3 ), V–Al–C (V 3 AlC 2 and V 4 AlC 3 ), V–Cr–Al–C ((V 0.5 Cr 0.5 ) 3 AlC 2 and (V 0.5 Cr 0.5 ) 5 Al 2 C 3 ), Ta–Al–Sn–C (Ta 3 Al 0.6 Sn 0.4 C 2 ), Ta–Al–C (α-Ta 4 AlC 3 , β-Ta 4 AlC 3 , β-Ta 6 AlC 5 ), Nb–Al–C (Nb 4 AlC 3 ), and Ti–Nb–Al–C ((Ti,Nb) 5 AlC 4 ) systems. The synthesis processes of new phases were introduced and the crystal parameters, atomic stacking sequences, as well as the atomic positions and basic physical and mechanical properties, of these new MAX phases were systemically described. Additionally, the possible directions and techniques of discovering new more MAX phases were summarized.