Optical Determination of Cuprous Oxide at Zinc Oxide—Metal Interface of an Oxidized α-Brass

Abstract

During brass oxidation, a copper diffusion is observed at the zinc oxide/metal interface, in the case of high temperature oxidation (T > 400 °C). Optical methods like FTIR and photoluminescence are used to characterize the oxidized form of copper located at metal—oxide interface. Detection of the vibrational transverse mode at 610 cm−1 and luminescence emissions attributed to copper and oxygen vacancies allow the characterization of copper oxidized form (copper I oxides) located at metal/oxide interface in agreement with SIMS results. But, the displacement reaction (Cu2O + Zn → 2 Cu + ZnO) could also occur according to thermodynamic data; so, the copper is in the oxidized form and eventually metallic.

Optical Enhancement of Fingerprint Deposits on Brass Using Digital Color Mapping

“…It can be seen that the Zn/Cu ratio is similar for both areas demonstrating that heating the brass causes a movement of zinc toward the surface of the metal irrespective of whether it is able to be oxidized at the surface. This migration has been observed previously for heated α‐phase brass (18), and it is well known that dezincification (the loss of zinc) is accelerated as temperature increases (19). Metallic zinc and copper were present on the surface of the overlaid area at higher temperatures than on the nonoverlaid area and, while oxides of both elements were present in both areas, AES showed the concentration of zinc and copper atoms to be much greater than the concentration of ions in the overlaid area.…”

Visualization of Latent Fingermark Corrosion of Brass, Climatic Influence in a Comparison Between the U.K. and Iraq

“…Beucher et al. used this technique to characterize the oxidation state of copper on oxidized α phase brass (28) and produced a luminescence model for both copper (I) oxide and zinc oxide. Beucher et al.…”

“…Beucher et al. (28) also employed Fourier transform infrared spectroscopy to detect vibrational modes in both oxides, and both of these techniques offer possibilities to enhance the visualization of fingermark corrosion of brass.…”

“…As well as optical absorption, both copper (I) oxide and zinc oxide are luminescent and offer the possibility of fingermark ridge detail visualization through photoluminescence. Beucher et al used this technique to characterize the oxidation state of copper on oxidized a phase brass (28) and produced a luminescence model for both copper (I) oxide and zinc oxide. Beucher et al (28) also employed Fourier transform infrared spectroscopy to detect vibrational modes in both oxides, and both of these techniques offer possibilities to enhance the visualization of fingermark corrosion of brass.…”

Effect of Temperature on Rectifying Schottky Barriers Formed from Fingerprint Sweat Corrosion of Brass

“…Complementing research on saline (1,3–5) and elevated temperature corrosion of brass (14), in this technical note, we examine how increased temperature affects the relative abundance of fingerprint sweat corrosion products and rectifying contact formation. Such studies are of importance to those engaged in researching the recovery of fingerprints from brass shell casings (15) or arson crime scenes (16).…”