Determination of trace impurities in sintered aluminium nitride and boron nitride by pressure acid decomposition/ICP-AES

Abstract

Several decomposition methods were examined to determine impurities in sintered aluminium nitride and boron nitride samples. The pulverized samples were severely contaminated. A lump (about 0.3 g) of sintered aluminum nitride sample was decomposed with 15 ml of hydrochloric acid at 200°C, or 10 ml of sulfuric acid (1+2) at 230°C in a Teflon pressure vessel. Similarly sintered boron nitride samples were decomposed with a mixture of 7.5 ml of hydrofluoric acid and 2.5 ml of hydrochloric acid at 200°C. Several commercial samples were decomposed by the proposed methods, and impurities were determined by ICP-AES.