Determine the cause of the drifting resistance–temperature relationship

Determine the exact cause of the observed decrease toward an asymptotic limit in the measured resistance–temperature relationship of the uncoated Protochips Fusion SiC-based MEMS heating-chip membrane across repeated temperature-cycling measurements, including whether it results from prolonged storage in air, annealing-induced changes in the membrane, or another mechanism.

Background

Repeated calibration measurements show that the measured resistance–temperature curves decrease as the number of thermal cycles increases, although the curves appear to approach an asymptotic limit. The resistance drift is larger at low temperatures and smaller at high temperatures, and the authors simulate its possible influence on the fitted thermal relaxation time.

The authors attribute the behavior tentatively to prolonged storage in air and/or annealing-induced changes in the chip membrane, but the mechanism remains unresolved. Establishing the cause would improve the reliability and reproducibility of resistance-based temperature calibration and thermal-response measurements for rapid-heating in-situ STEM experiments.