Comparative experimental studies of the specific heat of Fe and Ni using scanning calorimetry methods

Abstract

This study presents comparative experimental investigations of the specific heat of materials undergoing phase transitions, with the aim of assessing the capabilities and metrological limitations of differential scanning calorimetry methods and instrumentation. Nickel and iron were selected as reference materials due to the availability of reliable literature data for verification. Two approaches to determining heat flux density in differential scanning calorimetry were compared using three calorimeters: Pyris 1 (PerkinElmer), DSC 3 (Mettler Toledo), and DSC 404 F1 Pegasus (Netzsch). Measurements were conducted in a protective atmosphere over a temperature range up to 600°C on samples that had been thermally stabilised prior to testing. For the Pyris 1 calorimeter, a proprietary measurement procedure based on heating and cooling cycles with isothermal holds was applied, enabling reliable determination of specific heat during heating and cooling. In contrast, for the DSC 3 and DSC 404 F1 instruments, the analysis was primarily based on heating data. The obtained results allowed analysis of the second-order phase transition in nickel, including determination of the transition end temperature and the temperature corresponding to the maximum differential scanning calorimetry peak. The phase transition in iron was characterised solely using data from the DSC 404 F1 instrument, due to measurement limitations of the remaining equipment. Additionally, three independent temperature-dependent specific heat characteristics were compared, obtained using a relative method with identical reference standards and standard differential scanning calorimetry signal conversion procedures. The results contribute to improved understanding of calorimetry methodology and measurement uncertainty in materials undergoing phase transitions.