Unprecedented switching endurance affords for high-resolution surface temperature mapping using a spin-crossover film.

Ridier, Karl; Bas, Alin-Ciprian; Zhang, Yuteng; Routaboul, Lucie; Salmon, Lionel; Molnár, Gábor; Bergaud, Christian; Bousseksou, Azzedine · Nat Commun · 2020

basic_science · Level V

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Abstract

Temperature measurement at the nanoscale is of paramount importance in the fields of nanoscience and nanotechnology, and calls for the development of versatile, high-resolution thermometry techniques. Here, the working principle and quantitative performance of a cost-effective nanothermometer are experimentally demonstrated, using a molecular spin-crossover thin film as a surface temperature sensor, probed optically. We evidence highly reliable thermometric performance (diffraction-limited sub-µm spatial, µs temporal and 1 °C thermal resolution), which stems to a large extent from the unprecedented quality of the vacuum-deposited thin films of the molecular complex [Fe(HB(1,2,4-triazol-1-yl)<sub>3</sub>)<sub>2</sub>] used in this work, in terms of fabrication and switching endurance (>10<sup>7</sup> thermal cycles in ambient air). As such, our results not only afford for a fully-fledged nanothermometry method, but set also a forthcoming stage in spin-crossover research, which has awaited, since the visionary ideas of Olivier Kahn in the 90's, a real-world, technological application.