Perturbation theories behind thermal mode spectroscopy for high-accuracy measurement of thermal diffusivity of solids

ABSTRACT

Thermal mode spectroscopy (TMS) has been recently proposed for accurately measuring thermal diffusivity of solids from a temperature decay rate of a specific thermal mode selected by three-dimensional (anti)nodal information [Phys. Rev. Lett., 117, 195901 (2016)]. In this paper, we find out the following advantages of TMS by use of perturbation analyses. First, TMS is applicable to the measurement of high-thermal diffusivity with a small-size specimen. Second, it is less affected by thermally resistive films on a specimen in the sense that the resistance at the interface does not affect the first-order correction of thermal diffusivity. Third, it can perform doubly accurate measurement of the thermal diffusivity specified at a thermal equilibrium state even if the diffusivity depends on temperature in the sense that the measurement can be performed within tiny temperature difference from the given state and that the decay rate of the slowest decaying mode is not affected by the dependence.

KEYWORDS:

• Thermal conductivity
• thermal mode spectroscopy
• perturbation theory
• thermal equilibrium state

Acknowledgments

HI is grateful to Dr. G. Kawahara and Dr. M. Shimizu of Osaka University, and Dr. E. Sasaki of Akita University for valuable comments and discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by JSPS KAKENHI [grant number JP16K13719].