Synthesis of binary copper chalcogenides by mechanical alloying

Abstract

Copper sulfides (tetragonal Cu 1.92S-Cu 1.99S, rhombohedral Cu 1.71S-Cu 1.89S, CuS), selenides (β Cu 2 − xSe, Cu 3Se 2, γ CuSe, CuSe 2), and tellurides (Cu 2 − xTe, Cu 3Te 2) were prepared from mixtures of the elements by mechanical alloying (MA), using a high-energy ball mill. The compounds were obtained by 60–120 min of MA. It is notable that two metastable high-pressure phases were obtained by MA: tetragonal Cu 2 − xS and pyrite-type CuSe 2. The tetragonal phase gradually transformed to the stable phase of djurleite when kept at room temperature. Cu 1.71S-Cu 1.89S also formed a metastable rhombohedral phase.