Determination of thermal diffusivity of opaque materials using the photothermal mirror method

Aristides Marcano; Gabriel Gwanmesia; Mark King; Daniel Caballero

doi:10.1117/1.OE.53.12.127101

8 December 2014 Determination of thermal diffusivity of opaque materials using the photothermal mirror method

Aristides Marcano, Gabriel Gwanmesia, Mark King, Daniel Caballero

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Optical Engineering, Vol. 53, Issue 12, 127101 (December 2014). https://doi.org/10.1117/1.OE.53.12.127101

Abstract

A pump-probe photothermal mirror (PTM) method has been developed to determine the thermal diffusivity of opaque solid samples. The method involves the detection of the distortion of a probe beam whose reflection profile is affected by the photoelastic deformation of a polished material surface induced by the absorption of a focused pump field. We have measured the time dependence of the PTM signal of Ti, Al, Cu, Sn, Ag, and Ni samples. We show theoretically and experimentally that the time derivative of the signal in the first microseconds is proportional to the square root of the thermal diffusivity coefficient. The method affords a simple calibration and efficient interpretation of experimental data for a sensitive determination of the thermal diffusivity coefficient for materials. We demonstrate the applicability of the technique by measuring the thermal diffusivities of wadsleyite (β-Mg₂SiO₄) and diopside (MgCaSi₂O₆), two important minerals relevant to geophysical studies.

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Aristides Marcano, Gabriel Gwanmesia, Mark King, and Daniel Caballero "Determination of thermal diffusivity of opaque materials using the photothermal mirror method," Optical Engineering 53(12), 127101 (8 December 2014). https://doi.org/10.1117/1.OE.53.12.127101

Published: 8 December 2014

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