The spectral emissivity of iron and molybdenum has been investigated as a function of wavelength in the visible spectrum. A gradual rise in the emissivity for both metals was observed as the blue end of the spectrum is approached. The increase in the emissivity of iron with decrease in wavelength is much greater than that observed for molybdenum. The emissivity of iron in the body-centered form at temperatures below 1178°K is observed to be higher at all wavelengths than it is for the higher temperature face centered cubic form.
JACK ELDON TAYLOR, "The Variation with Wavelength of the Spectral Emissivity of Iron and Molybdenum," J. Opt. Soc. Am. 42, 33-33 (1952)