AbstractAmorphous 55wt%Cr-45wt%Ni films (60 nm thick) supported on EM copper grids were irradiated in air at normal incidence with a ruby laser (λ∼, 0.694 μm) through a ≈ 1.5 mm diameter diaphragm using one single laser pulse of 60 ns (FWHM) with fluences ranging from 120 to 540 J.m−2. The structure of the irradiated films is studied by TEM and TED. As a rule due to the appearance of thermal gradients between the centre and the mesh edge of the EM grid, the crystallization took place under various conditions of reaction from liquid phase, liquid melted layers , activated diffusion in solid state, to under threshold conditions for the development of the crystalline nuclei in the amorphous matrix. Periodic resonant and unreso-nant structures also developed in the liquid melted layers.