  One of issues arising in materials science is a behavior of non-equilibrium
point defects in the atomic lattice, which defines the rates of chemical
reactions and relaxation processes as well as affects the physical properties
of solids. It was previously predicted that melting and rapid solidification of
metals and alloys provides a vacancy concentration in the quenched material,
which can be comparable to that quantity at the point of melting. Here, we
experimentally explore the vacancy behavior in thin films of the
quasi-equiatomic Fe-Al alloy subjected to nanosecond laser annealing with
intensities up to film ablation. The effects of laser irradiation are studied
by monitoring magneto-optically the ordering kinetics in the alloy at the very
ablation edge, within a narrow (micron-scale) ring-shaped region around the
ablation zone. Quantitatively, the vacancy supersaturation in the quenched
alloy has been estimated by fitting a simulated temporal evolution of the
long-range chemical order to the obtained experimental data. Laser quenching
(LQ) of alloys and single-element materials would be a tool for obtaining novel
phase states within a small volume of the crystal.
