Microstructure and optical properties of lustre glazes produced on a copper body

In this research, a luster enamel is applied to a copper body. A white glaze, conventionally applied in enamel handcraft, was used as the luster substrate. Silver nitrate was used as the source of the lustre metal. Since the work aimed to determine the optimal firing conditions, several samples were prepared with different reduction temperatures and times. The optimal firing temperature and reduction time were found to be 600 °C and 10 min, respectively. The microstructure and chemical analyses were performed on the samples using an FE-SEM image. The results showed the successful formation of silver nanoparticles within the glaze substrate. In addition, two layers were formed: a thin glass layer of several tens of nm on the surface and a layer containing silver nanoparticles inside the glaze. The results also showed that the silver nanoparticles can penetrate several microns into the glaze body. Reflectance spectra confirmed the presence of silver nanoparticles in the lustre with a volume fraction of order of 0.01%.