Formation of new copper antimony oxides by solid state reaction between CuSb 2O 6 and CuO under atmospheric and high pressure

Abstract

Two kinds of new copper antimony oxides, Cu(I) 4SbO 4.5 and Cu(II) 9Sb 4O 19, were produced by solid state reaction between CuSb 2O 6 and CuO at 1120–1150 °C in atmosphere and at 1000–1100 °C under a solid pressure of 10 kbar or an oxygen pressure of 10 bar, respectively. This Cu 4SbO 4.5 was in a different form, called form II, from form I of Cu 4SbO 4.5 resulting from thermal decomposition of CuSb 2O 6 in an oxygen-free atmosphere. X-ray powder diffraction pattern of Cu 9Sb 4O 19 was indexed on the basis of body-centered cubic unit cell with a o = 9.620 A. This oxide was found to decompose to Cu 4SbO 4.5 + CuSb 2O 6 with evolution of oxygen at 950–990°C in air by TG and DTA.