Boltzmann-Distribution-Driven Cathodoluminescence Thermometry in In Situ Transmission Electron Microscopy.

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• In situ transmission electron microscopy (TEM) enables real-time observation of material mechanisms.
• Accurate local temperature probing is crucial for understanding dynamic processes in heterogeneous matter.

Purpose of the Study:

• To introduce a novel Boltzmann-distribution-driven cathodoluminescence (CL) nanothermometry technique.
• To enable precise, in situ local temperature measurements within a TEM environment.

Main Methods:

• Utilizing the Boltzmann distribution of Stark sublevels in dysprosium-doped yttrium vanadate.
• Employing the CL-intensity ratio for temperature sensing across a broad temperature range (103-435 K).

Main Results:

• Achieved relative sensitivity exceeding 3% K⁻¹ and precision of ±2%.
• Demonstrated independence from electron-beam parameters and dopant concentration, enhancing robustness.
• Successfully performed real-time temperature distribution mapping on a TEM grid under laser irradiation.

Conclusions:

• The developed CL nanothermometry provides a reliable and versatile tool for in situ temperature measurements in electron microscopy.
• This technique significantly advances the capability for real-time thermal analysis of materials at the nanoscale.