Fabrication of Bismuth Films by a Melt Spinning Method and the Influence of Annealing on Their Microstructure

The conditions of fabrication of bismuth films with thickness from 5 to 30 μm by a melt spinning method were studied. The microstructure of the fabricated films in the cross section was analyzed using SEM. The Bi films with thickness more than 5 μm consisted of crystallites with sizes up to 30 μm and had a layered structure with crystal twins. The films with thickness of ~5 μm contained no crystallites, however, after annealing at 150–200°C for 1 h, there appeared bismuth nanocrystals with sizes from 10 to 100 nm. Annealing at higher temperatures promoted an increase in the size of nanocrystals and formation of crystallites of pyramidal shape with sizes up to 500 nm.