We report the microfabrication and operation of a highly sensitive ac-calorimeter designed to characterize small mass magnetic systems operating at very low frequencies (from 0.1 to 5 Hz) in a temperature range from 20 to 300 K. The calorimetric cell is built in the center of a 500 nm thick polymeric membrane of parylene held up by a Cu frame. With these characteristics the frequency of adiabaticity is typically around few hertz and energy exchanges as small as 1pJ can be detected. Measurements have been performed on Co/Au thin films and on the GdAl 2 microcrystal where the ferromagnetic phase transition is clearly evidenced.
|Translated title of the contribution||Parylene self-suspended measurement cell by nanocalorimetric alternative method|
|Number of pages||18|
|Journal||Instrumentation Mesure Metrologie|
|Publication status||Published - 2011|