Dual-Wavelength Laser Flash Raman Spectroscopy Method for In-Situ Measurements of the Thermal Diffusivity: Principle and Experimental Verification
| Autor: | Xing Zhang, Haidong Wang, Yudong Hu, Weigang Ma, Aoran Fan |
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| Rok vydání: | 2019 |
| Předmět: |
Accuracy and precision
Materials science Silicon business.industry 020209 energy chemistry.chemical_element 02 engineering and technology Condensed Matter Physics Thermal diffusivity Laser law.invention symbols.namesake Wavelength 020303 mechanical engineering & transports Optics 0203 mechanical engineering chemistry law Temporal resolution Thermal 0202 electrical engineering electronic engineering information engineering symbols business Raman spectroscopy |
| Zdroj: | Journal of Thermal Science. 28:159-168 |
| ISSN: | 1993-033X 1003-2169 |
| Popis: | This paper presents an in-situ, non-contact, non-destructive “dual-wavelength laser flash Raman spectroscopy method” for measuring the thermal diffusivity. In this method, a heating pulse is used to heat the sample and another pulsed laser with a different wavelength and negligible heating effect is used as a probe to measure the sample temperature changes during the heating and cooling periods from the Raman peak shifts. The sample temperature rise and fall curves are measured by changing the delay between the heating pulse and the probing pulse with the thermal diffusivity then characterized by fitting the temperature curves. The time delay between the heating and probing pulses can be precisely controlled with a minimum step of 100 ps. Hence, the temperature variation can be scanned with an ultra-high temporal resolution of up to 100 ps, which significantly improves the measurement accuracy of transient thermal parameters. The measurement accuracy of this method has been verified using a bulk material model and experiments. The measured thermal diffusivity of a silicon sample has been obtained to be 8.8×10-5 m2/s with a 3% difference between the measured value and the average result for bulk silicon in the literature which verifies the reliability and accuracy of this method. |
| Databáze: | OpenAIRE |
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