Analysis of the structural evolution of Ce and La-based metallic glasses during annealing

Metallic glasses are a class of materials developed since the 1960s that have gained increasing interest due to their unique properties. Among the most important aspects to study for potential applications are thermal stability and the thermally induced transformations that the material might undergo during use. This study aims to investigate the structural changes that a family of metallic glasses of composition (CexLa1-x)65Al10Co25 (x=1, 0.7, 0.6, 0.5, 0.4, 0.3, 0) undergoes when heated from room temperature to about 370ºC. The analyzed samples are in the form of ribbons produced using the single wheel melt spinning technique. Combining Differential Scanning Calorimetry (DSC) analysis with Small-Angle X-ray Scattering (SAXS), Wide-Angle X-ray Scattering (WAXS) and Focused Ion Beam Scanning Electron Microscopy (FIBSEM) analyses allowed for the comparison of the structures of various samples in terms of system order and density as the temperature increased. The study concluded that, following an initial structural relaxation present for each composition, a liquid-liquid transition occurs, in some cases accompanied by what could be a dissociation of the resulting liquid and finally phenomena of nanocrystallization and crystal growth.