Chemical States of Copper and Tin in Copper Glazes Fired under Various Atmospheres

Abstract

R — O , N — R , and O — R firing operations produce copper red glazes resulting from the formations of Cu 2 O, metallic copper, and both Cu 2 O and metallic copper, respectively. The symbols O , N , and R denote oxidizing, neutral, and reducing atmospheres, respectively, and in the set of symbols, the former corresponds to the heating atmosphere and the latter to the successive cooling atmosphere. All other firing operations such as R — R and R — N fail to produce red glazes. The formation mechanisms of metallic copper and Cu 2 O are postulated from a microscopic viewpoint.