Nanocalorimetry of Nanoscaled Ni/Al Multilayer Films: On the Methodology to Determine Reaction Kinetics for Highly Reactive Films

Abstract

Free‐standing Ni/Al multilayer films with a planar morphology, a bilayer thickness of 20 nm, and an average composition of Ni50Al50 (at%) deposited by direct current magnetron sputtering are investigated by nanocalorimetry and conventional calorimetry. Both the novel fast differential scanning calorimeter (FDSC) Flash DSC 2+ from Mettler–Toledo (MT) and conventional calorimeter MT DSC 3 are used to cover a range of heating rates from 0.1 to 104 K s−1. A quantitative kinetic study of the interdiffusion and phase reaction sequence is performed via a Kissinger analysis covering five orders of magnitude of heating rates. Using the calorimetric data, the derived apparent activation energies suggest monotonic reaction kinetics over the entire range of heating rates applied. To correct the thermal lag at the highest heating rates with the FDSC for nonadhered free‐standing films, a new methodology for its correction is used. Overall, this work extends the application of commercial FDSC to nonadhered films.