Determination of Rare Impurities in High-Purity Germanium and Germanium Oxide by Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract

We have proposed a combination of techniques for quantitative chemical analysis of high-purity germanium and germanium oxide by inductively coupled plasma atomic emission spectrometry. The techniques are intended for determination of the rare-earth (RE) elements (except Pm), platinum group metals (PGMs) (except Os), I, S, Th, Tl, and U after acid dissolution of a sample (instrumental technique) and after separation of the matrix in the form of a highly volatile compound (combined technique). The instrumental technique allows all of the above elements to be determined. To take into account the effect of germanium on analytical signals of analytes, use is made of Be, Dy, or Gd internal standards. The best results in spike experiments have been obtained for the RE elements, PGMs, and I with the Be 234.861 nm; for Th, Tl, and U with the Dy 353.170 nm; and for S with no internal standards. The analyte detection limits (DLs) lie in the range n × 10–6 to n × 10–5 wt %. The combined technique is intended for lowering the DLs for Ir, Pd, Pt, Rh, Ru, S, Th, Tl, and U. Germanium was removed from weighed samples of germanium metal and germanium dioxide in the form of GeCl4 to above 99.99%. The analyte DLs were then from n × 10–7 to n × 10–6 wt %.