Solid-State Displacement Reaction between Chromium and Cuprous Oxide

Abstract

The solid-state displacement reaction between Cr and Cu₂O was carried out in argon at 1173 K and 1273 K. The product zone consisted of three layers of Cr₂O₃, Cu+CuCrO₂ two-phase product and Cu. The Cu and Cu+CuCrO₂, two-phase layer grew as one aggregate layer. The Cr₂O₃ layer once formed became thinner during the reaction and correspondingly the Cu+CuCrO₂ layer became thicker. The consumption of Cr₂O₃ is considered to be due to the side reaction 2Cu+O+Cr₂O₃=2CuCrO₂. The stability of the reaction products is discussed on the basis of the phase diagram of the Cu–Cr–O system.