High-speed dynamics of temperature distribution in ultrafast (up to 10~8 K/s) chip-nanocalorimeters, measured by infrared thermography of high resolution

摘要

To study the kinetics of phase transitions and to obtain artificial materials with improved physical properties, a set of thin-film high-sensitivity sensors for ultra-fast scanning nanocalorimetry has been constructed. To investigate the dynamics of the temperature distribution in thin-film calorimetric sensors, high-resolution high-speed infrared thermography has been applied as a tool of non-contact thermal imaging in combination with ultra-fast scanning calorimetry. The dynamic heat-transfer problem, causing the temperature distribution in a thin-film sensor at ultrafast scanning of temperature, has been solved analytically. Analytical solutions for square and circular geometry have been obtained and compared with the temperature profiles obtained by infrared thermographic measurements. A theoretical background for ultra-fast-cooling experiments has been formulated. The origin of the restrictions imposed on the maximum attainable controlled cooling rate has been investigated. It is shown that thin-film sensors can be applied for controlled ultra-fast cooling, as well as heating, at 10(8) K/s and even 10(9) K/s.