{"title":"Measurement of thermal diffusivity and conductivity of thin films using laser-line lock-in thermography","authors":"Agustín Salazar, Arantza Mendioroz","doi":"10.1016/j.ijthermalsci.2025.109928","DOIUrl":null,"url":null,"abstract":"<div><div>Laser-line lock-in thermography consists in illuminating the sample surface with a modulated and focused laser beam and recording the spatial distribution of the temperature oscillations with an infrared camera. In this work we show that it is possible to measure the thermal diffusivity and conductivity of thin films. When the sample is in vacuum, both amplitude and phase of the temperature oscillations behave as a linear functions of the distance to the center of the illumination, and the thermal diffusivity can be obtained from their slopes. When the thin film is surrounded by air, the linearity of amplitude and phase is lost due to the influence of heat conduction to the air. In this case, the thermal conductivity of the material can be obtained by fitting the complete theoretical model (which includes all the heat transfer mechanisms) to the recorded experimental temperature profiles. Validation is performed on two thin films of different thermal transport properties.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"214 ","pages":"Article 109928"},"PeriodicalIF":4.9000,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Thermal Sciences","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1290072925002510","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Laser-line lock-in thermography consists in illuminating the sample surface with a modulated and focused laser beam and recording the spatial distribution of the temperature oscillations with an infrared camera. In this work we show that it is possible to measure the thermal diffusivity and conductivity of thin films. When the sample is in vacuum, both amplitude and phase of the temperature oscillations behave as a linear functions of the distance to the center of the illumination, and the thermal diffusivity can be obtained from their slopes. When the thin film is surrounded by air, the linearity of amplitude and phase is lost due to the influence of heat conduction to the air. In this case, the thermal conductivity of the material can be obtained by fitting the complete theoretical model (which includes all the heat transfer mechanisms) to the recorded experimental temperature profiles. Validation is performed on two thin films of different thermal transport properties.
期刊介绍:
The International Journal of Thermal Sciences is a journal devoted to the publication of fundamental studies on the physics of transfer processes in general, with an emphasis on thermal aspects and also applied research on various processes, energy systems and the environment. Articles are published in English and French, and are subject to peer review.
The fundamental subjects considered within the scope of the journal are:
* Heat and relevant mass transfer at all scales (nano, micro and macro) and in all types of material (heterogeneous, composites, biological,...) and fluid flow
* Forced, natural or mixed convection in reactive or non-reactive media
* Single or multi–phase fluid flow with or without phase change
* Near–and far–field radiative heat transfer
* Combined modes of heat transfer in complex systems (for example, plasmas, biological, geological,...)
* Multiscale modelling
The applied research topics include:
* Heat exchangers, heat pipes, cooling processes
* Transport phenomena taking place in industrial processes (chemical, food and agricultural, metallurgical, space and aeronautical, automobile industries)
* Nano–and micro–technology for energy, space, biosystems and devices
* Heat transport analysis in advanced systems
* Impact of energy–related processes on environment, and emerging energy systems
The study of thermophysical properties of materials and fluids, thermal measurement techniques, inverse methods, and the developments of experimental methods are within the scope of the International Journal of Thermal Sciences which also covers the modelling, and numerical methods applied to thermal transfer.