Methods for Calibration of Specimen Temperature During In Situ Transmission Electron Microscopy Experiments

Abstract

One of the biggest challenges for in situ heating transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) is the ability to measure the local temperature of the specimen accurately. Despite technological improvements in the construction of TEM/STEM heating holders, the problem of being able to measure the real sample temperature is still the subject of considerable discussion. In this study, we review the present literature on methodologies for temperature calibration. We analyze calibration methods that require the use of a thermometric material in addition to the specimen under study, as well as methods that can be performed directly on the specimen of interest without the need for a previous calibration. Finally, an overview of the most important characteristics of all the treated techniques, including temperature ranges and uncertainties, is provided in order to provide an accessory database to consult before an in situ TEM/STEM temperature calibration experiment.

Atomic-Resolution Cryo-STEM Across Continuously Variable Temperatures

“…2b). We observed no change in performance with activation of the MEMS heater during experiments up to temperatures of 823 K. In line with our measurements, the temperature stability, precision, control, and uniformity in similar MEMS chips are well documented up to the maximum temperatures, usually ~1073 K (800°C) (Allard et al, 2009; Mele et al, 2016; Perez-Garza et al, 2016; van Omme et al, 2018; Gaulandris et al, 2020). Cooled to the cryogenic baseline of ~100 K without MEMS heating (Fig.…”

Quo Vadis Micro-Electro-Mechanical Systems for the Study of Heterogeneous Catalysts Inside the Electron Microscope?

“…Moreover, with a high gas flow through the nanoreactor there is a temperature gradient along the gas channel [59]. A review of methods for temperature calibration in in situ experiments was recently published by Gaulandris et al [112]. Such temperature gradients could cause the reaction of interest to proceed with uneven kinetics across the catalyst bed [113].…”

Quantification of extreme thermal gradients during in situ transmission electron microscope heating experiments

“…Therefore, new approaches are needed, to study thermally activated phenomena in materials in real time under such conditions. Existing MEMS‐based in situ TEM heating devices can rapidly heat and cool samples under isothermal conditions (Allard et al, 2009; Gaulandris et al, 2020; Mele et al, 2016; Spruit et al, 2017). However, MEMS‐based in situ TEM heating device that can generate large thermal gradients combined with the capability to thermally cycle a specimen between different temperatures are not available.…”

“…The new generation of micro-electro-mechanical systems (MEMS)-based heating holders were developed to mitigate these limitations and are, therefore, nowadays widely used for in situ TEM studies (Allard et al, 2009;Kumar et al, 2020;Mele et al, 2016;Pérez Garza et al, 2017;Van Huis et al, 2009;van Omme, Zhakozheva, Spruit, Sholkina, & Perez-Garza, 2018). These advanced MEMS-based holders are advantageous as a result of: (1) the small thermal mass of MEMS microheaters resulting in reduced sample drift (Allard et al, 2009;Gaulandris et al, 2020;Perez-Garza et al, 2016), (2) the fast heater response time enabling rapid heating and cooling experiments (up to 10 6 C/s) (Allard et al, 2009;Gaulandris et al, 2020;Mele et al, 2016;Spruit, van Omme, Ghatkesar, & Perez-Garza, 2017), and (3) the high temperature homogeneity (~99%) across the membrane and the sample within the viewing area (Mele et al, 2016;Spruit et al, 2017;, which allows for reliable and reproducible in situ TEM heating experiments.…”