Optical properties and electronic structure of the Cu–Zn brasses

V.J. Keast (1) , J. Ewald (1) , K.S.B. de Silva (2) , M.B. Cortie (2) , B. Monnier (3, 1) , D. Cuskelly (1) , E.H. Kisi (1)

1 UoN - University of Newcastle [Australia]
2 UTS - University of Technology Sydney
3 UTT - Université de Technologie de Troyes

The color of Cu–Zn brasses range from the red of copper through bright yellow to grey-silver as the Zn content increases. Here we examine the mechanism by which these color changes occur. The optical properties of this set of alloys has been calculated using density functional theory (DFT) and compared to experimental spectroscopy measurements. The optical response of the low Zn content α-brasses is shown to have a distinctly different origin to that in the higher content β′, γ and ε-brasses. The response of β′-brass is unique in that it is strongly influenced by an overdamped plasmon excitation and this alloy will also have a strong surface plasmon response.

Keywords: Metals and alloys; Dielectric response; Density functional theory; Optical spectroscopy

Domains: Optics [physics.optics]; Materials

V.J. Keast, J. Ewald, K.S.B. de Silva, M.B. Cortie, B. Monnier, et al.. Optical properties and electronic structure of the Cu–Zn brasses. Journal of Alloys and Compounds, 2015, 647, pp.129-135. ⟨10.1016/j.jallcom.2015.06.136⟩. ⟨hal-02439668⟩