Structural changes occurring in an Fe 72.5 Cu 1 Nb 2 Mo 2 Si 15.5 B 7 alloy during a combination of constant rate heating (20 K/min) and isothermal holding at 500 and 520 • C were investigated using in-situ high-energy X-ray diffraction. We found that the ferromagnetic-to-paramagnetic transition of an amorphous phase is revealed as a change of the slope of the thermal expansion curve when heating a sample with a constant rate up to 520 • C. Real space analysis by means of atomic pair

more »

... n function (PDF) demonstrated that the rate and extent of the thermal expansion strongly depends on the interatomic separation. PDF proved to be a reliable method for the description of crystallization kinetics. Further it allows determination of sizes of ultrafine nanocrystals with grain sizes well below 8 nm and thus makes observation of early stages of nanocrystallization possible. Following grain growth kinetics during isothermal annealing at 500 and 520 • C we found that the activation energy of the process is 357±12 kJ/mol.