New phases’ discovery in MAX family

Present work reviewed the discovery of new MAX phases since 2004. To date, there were new compounds synthesized in the Ti–Si–C (Ti4SiC3, Ti5Si2C3 and Ti7Si2C5), Ti–Al–C (Ti5Al2C3), Ti–Ge–C (Ti4GeC3, Ti5Ge2C3 and Ti7Ge2C5), Ti–Sn–C (Ti3SnC2), Ti–Ga–C (Ti4GaC3), V–Al–C (V3AlC2 and V4AlC3), V–Cr–Al–C ((V0.5Cr0.5)3AlC2 and (V0.5Cr0.5)5Al2C3), Ta–Al–Sn–C (Ta3Al0.6Sn0.4C2), Ta–Al–C (α-Ta4AlC3, β-Ta4AlC3, β-Ta6AlC5), Nb–Al–C (Nb4AlC3), and Ti–Nb–Al–C ((Ti,Nb)5AlC4) 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.

► Present work reviewed the discovery of new MAX phases since 2004.
► The crystal structure, atomic positions, and properties of new MAX phases were described.
► The possible research directions and techniques of discovering new more MAX phases were summarized.