GRK researchers achieve precision record for in situ thermometry

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In situ temperature measurement with Sub-Kelvin accuracy achieved in a DENSsolutions Climate Nano-Reactor. From, under a CC-BY 4.0 license.

In a recent paper published in Ultramicroscopy ( by researchers from the GRK projects A2, A1, and Z, together with Fraunhofer IISB, and DENSsolutions, sub-Kelvin accuracy temperature measurement was demonstrated during in operando analysis of an in situ gas cell TEM heating system. By tracking the thermal expansion of gold nanoparticle ensembles via parallel-beam electron diffraction (PBED), a technique developed in this GRK, local temperature fluctuations were observed with an accuracy of ±0.36 K, equaling a relative precision of 5 ppm. This temperature resolution is as high as in XRD analysis and was achieved by a joint effort of advanced data analysis, mitigation of charging artefacts, and a high area density of gold nanothermometers. It was harnessed to quantify the mean local thermal stability of a DENSsolutions Climate Nano-Reactor between 100 and 1000 °C setpoint temperature for different operation conditions, revealing that thermal fluctuations remain below 2 K.
Congratulations to Birk Fritsch, Mingjian Wu, Andreas Hutzler, Dan Zhou, Ronald Spruit, Lilian Vogl, Johannes Will, H. Hugo Pérez Garza, Martin März, Michael Jank, and Erdmann Spiecker.