  MAB phases are a new class of layered ternary materials that have already
shown a number of outstanding properties. Here, we investigate defect evolution
and radiation tolerance of two MAB phases, MoAlB and Fe2AlB2, using a
combination of experimental characterization and first-principles calculations.
We find that Fe2AlB2 is more tolerant to radiation-induced amorphization than
MoAlB, both at 150 {\deg}C and at 300 {\deg}C. The results can be explained by
the fact that the Mo Frenkel pair is unstable in MoAlB and as a result,
irradiated MoAlB is expected to have a significant concentration of MoAl
antisites, which are difficult to anneal even at 300 {\deg}C. We find that the
tolerance to radiation-induced amorphization of MAB phases is lower than in MAX
phases, but it is comparable to that of SiC. However, MAB phases do not show
radiation-induced cracking which is observed in MAX phases under the same
irradiation conditions. This study suggests that MAB phases might be a
promising class of materials for applications that involve radiation.
