Liquid-phase behaviour of normal spectral emissivity at 684.5 nm of some selected metals

A submicrosecond-resolution laser polarimeter (μs-DOAP) was used to measure normal spectral emissivity at 684.5 nm in the liquid phase of a range of pulse-heated metals. The metals under investigation were tungsten, tantalum, niobium, zirconium, nickel, copper, silver, and platinum in the temperature range from some hundred degrees below the melting point up into the stable liquid phase. Data for the normal spectral emissivity of these metals are presented and three different behaviours of normal spectral emissivity in the liquid phase have been observed: increasing, constant, or decreasing throughout the liquid phase depending on the material. Additionally, normal spectral emissivity of platinum shows an up-to-now unobserved solid state behaviour before the melting transition.