Optical Absorption in the Visible Range of Cu_0.8−xZn_0.2Pd_x Alloys with 0 ≦ x ≦ 0.2 at Room Temperature¹)

Abstract

The optical absorptivity A of Cuo.s-zZno.2Pd, alloys (0 5 z 5 0.2) was measured as a function of the wavelength between 250 nm < 1 < 800 nm a t room temperature in a vacuum system with < Torr. A has a peak (or shoulder) close to 380 nm for x = 0.1.The alloy with z = 0.2 has a minimum at this wavelength. It is proposed that palladium impurities are responsible for virtual energy states which lead to an increase in A below 300 nm and abovc 500 nm. Additionally palladium in higher concentrations absorbs part of the extra electrons of zinc in the copper-zinc matrix. This leads to the minimum of A in the alloy with 20 atyo palladium.