Fig. 4

Formation of fcc structural solid solutions in seven MAX phases. Grazing incidence X-ray diffraction patterns of Ti₃AlC₂ (a), Ti₂AlC (b), Ti₃SiC₂ (c), Nb₄AlC₃ (d), V₂AlC (e), Ti₄AlN₃ (f), and Ti₂AlN (g), respectively. Nb₄AlC₃ was irradiated with 70 KeV He ions and the rest were irradiated with 1 MeV Au ions. There emerge three new diffraction peaks (111, 200, and 220) characteristic of the fcc phases following irradiation, which are indicated by triangles. This indicates that all of these compounds transform from the initial hexagonal structures to fcc structures. The peak positions of the fcc structures are all slightly different from those of their corresponding binary MX compounds