Fabrication of Nanostructured Metallized Glazes by Conventional Fast-Firing Route

A metallized glaze, suitable for large‐scale production, has been obtained starting from sepiolite‐n(Cu, Fe) as a stable vector containing the metal‐dispersed nanoparticles and following a conventional fast‐firing fabrication route. A small fraction of black carbon (about 4 wt%) was added to the starting mixture of the glaze to avoid oxidation of Cu nanoparticles in the 500°–700°C temperature range. At higher temperature (700°–1190°C), a fraction of the oxygen dissolved in the glassy phase is consumed by the Fe°/Fe2+ and Fe2+/Fe3+ redox reaction. Based on ellipsometric and quantitative optical reflectance measurements, it has been proven that the presence of a minimum concentration of Cu nanoparticles (∼10 vol%) in the top surface glaze layer is a prerequisite to obtain an appropriate metalize glaze.