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Microscale heating platforms capable of generating localized temperature rises can find applications in wide‐ranging areas including nanomaterials synthesis and microscale thermometry. Here, commercially available optical calibration samples called Ronchi rulings, which consist of an array of chrome lines on a float glass substrate, are demonstrated to serve as reconfigurable Joule heaters. Electrical connections are formed by wire bonding onto the chrome to Joule heat individual lines and monitor their temperature rises using electrical resistance thermometry. Tests across multiple heater lines demonstrate a negative temperature coefficient of resistance with an average value of −6.93 × 10−4 ± 8.18 × 10−5 K−1. Under Joule heating, temperature rises exceeding 100 K are measured. To characterize the temperature gradient across the chrome line and glass, a noncontact optical thermometry technique based on the temperature‐dependent luminescence of upconverting nanoparticles (UCNPs) is used, producing temperature measurements that match finite element simulations. A 1:1 area ratio between the chrome lines and glass offers a high probability of finding UCNPs across both materials. The temperature rise on chrome determined from luminescence thermometry, electrical resistance thermometry, and simulations are also consistent. Furthermore, over 50% of the peak temperature rise is maintained along the neighboring glass region.
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Automated plasmon peak fitting derived temperature mapping in a scanning transmission electron microscope
Nanoscale thermometry, an approach based on non-invasive, yet precise measurements of temperature with nanometer spatial resolution, has emerged as a very active field of research over the last few years. In transmission electron microscopy, nanoscale thermometry is particularly important during in situ experiments or to assess the effects of beam induced heating. In this article, we present a nanoscale thermometry approach based on electron energy-loss spectroscopy in a transmission electron microscope to measure locally the temperature of silicon nanoparticles using the energy shift of the plasmon resonance peak with respect to the zero-loss peak as a function of temperature. We demonstrate that using non-negative matrix factorization and curve fitting of stacked spectra, the temperature accuracy can be improved significantly over previously reported manual fitting approaches. We will discuss the necessary acquisition parameters to achieve a precision of 6 meV to determine the plasmon peak position.
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- Award ID(s):
- 1831406
- PAR ID:
- 10597543
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- AIP Advances
- Volume:
- 11
- Issue:
- 3
- ISSN:
- 2158-3226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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