RESUMO
A microelectromechanical-systems-based calorimeter designed for use on a synchrotron nano-focused X-ray beamline is described. This instrument allows quantitative DC and AC calorimetric measurements over a broad range of heating/cooling rates (≤100000â Kâ s(-1)) and temperature modulation frequencies (≤1â kHz). The calorimeter was used for high-resolution thermal imaging of nanogram-sized samples subjected to X-ray-induced heating. For a 46â ng indium particle, the measured temperature rise reaches â¼0.2â K, and is directly correlated to the X-ray absorption. Thermal imaging can be useful for studies of heterogeneous materials exhibiting physical and/or chemical transformations. Moreover, the technique can be extended to three-dimensional thermal nanotomography.