Emissivity modeling of metals during the growth of oxide film and comparison of the model with experimental results

Abstract

Emissivity modeling of metals has been developed to elucidate behavior during the growth of oxide film, and the modeling results have been compared with experimental results. To express emissivities, pseudo-optical constants of a bare metal and of an oxide film obtained by an elipsometer are substituted into the model equations. Emissivity behavior during the growth of an oxide film upon the surface of a specimen is shown in terms of spectral, directional, and polarized characteristics, and it coincides with the experimental results, both quantitatively and qualitatively. The modeling is simple and provides useful guidance for the development of emissivity-compensated radiation thermometry.

Emissivity measurements on aeronautical alloys

“…It is clear that the phonon frequencies change with temperature and the bands broaden due to a rise in the damping parameter of the oscillators. An appropriate modelling of the emissivity could be performed to obtain the oxide thickness, as well as the optical indices and the frequencies of the normal modes [14][15][16]. …”

Optical characterization of thin layers grown on metal components

“…the optical properties) is a key parameter for reliable results in the field of non-contact temperature measurements [6]. Due to interference effects during the growth of surface layers, the resulting spectral emissivity varies in a specific way [1,2,5]. As shown in this paper, these measured variations of emissivity allow the determination of the complex index of refraction of the film without explicit knowledge of the optical constants of the respective layers.…”

Radiation thermometry for silicon wafers

“…Extinction coefficients of both the oxide film and silicon wafer are negligible at a wavelength of 0.9 µm. The directional and polarized emissivities, ε p (θ) and ε s (θ), are obtained using the simulation model 22) . Figure 10 is a simulated result representing a relation between a ratio R ps and polarized emissivities of a specimen irrespective of emissivity variations due to the oxide film thickness, where R ps is the ratio of p-polarized radiance E p and s-polarized radiance E s at a wavelength of λ = 0.9 µm and an angle θ = 70º.…”