High - speed ( 104 ° C / s ) scanning microcalorimetry with monolayer sensitivity ( J / m 2 )

We introduce a high sensitivity (1J/m) scanning microcalorimeter that can be used at high heating rates (10 °C/s). The system is designed using ultrathin SiN membranes that serve as a low thermal mass mechanical support structure for the calorimeter. Calorimetry measurements of the system are accomplished via resistive heating techniques applied to a thin film Ni heating element that also serves as a thermometer. A current pulse through the Ni heater generates heat in the sample via Joule heating. The voltage and current characteristics of the heater were measured to obtain real-time values of the temperature and the heat delivered to the system. This technique shows potential for measuring irreversible heat of reactions for processes at interfaces and surfaces. The method is demonstrated by measuring the heat of fusion for various amounts of thermally evaporated Sn ranging from 50 to 1000 Å. © 1995 American Institute of Physics.