Location

La Jolla, CA

Start Date

1-1-1987 12:00 AM

Description

The experimental techniques and theory for utilizing the mirage effect, or optical probe beam detection, of thermal waves in opaque solids for determining their thermal diffusivities have been described in detail elsewhere. [1–4] An application to a coated nickel-based alloy has also been described elsewhere. [1] In previous papers [5,6] we presented a theoretical expression which describes the mirage effect signal in a three-layer medium (gas-coating-sample system), taking into consideration the effects of the sizes of the heating and probe beams. In this paper we extend the results of numerical calculations from that expression to the case of films which are thermally very thin (thicknesses of the order of 10-3 thermal diffusion lengths). A model system of 100–500 nm thick Cu films on glass substrates was studied experimentally at thermal wave frequencies below 1kHz, and in this paper we compare the results of those measurements to the numerical calculations.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

6B

Chapter

Chapter 7: Electronic Materials and Devices

Section

Electronic Materials and Devices

Pages

1347-1352

DOI

10.1007/978-1-4613-1893-4_152

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Thermal Wave Characterization of Coated Surfaces

La Jolla, CA

The experimental techniques and theory for utilizing the mirage effect, or optical probe beam detection, of thermal waves in opaque solids for determining their thermal diffusivities have been described in detail elsewhere. [1–4] An application to a coated nickel-based alloy has also been described elsewhere. [1] In previous papers [5,6] we presented a theoretical expression which describes the mirage effect signal in a three-layer medium (gas-coating-sample system), taking into consideration the effects of the sizes of the heating and probe beams. In this paper we extend the results of numerical calculations from that expression to the case of films which are thermally very thin (thicknesses of the order of 10-3 thermal diffusion lengths). A model system of 100–500 nm thick Cu films on glass substrates was studied experimentally at thermal wave frequencies below 1kHz, and in this paper we compare the results of those measurements to the numerical calculations.