Der Einfluss chemischer Reaktionen in Kohleelektroden auf die Intensität von Spektrallinien

Abstract

Thermochemical reactions taking place in graphite electrodes if burnt in a d.c. are and their influence on the intensity of spectral lines have been investigated. For this purpose SiO 2, TiO 2, ZrO 2, V 2O 5, MoO 3, WO 3, MnO 2, NiO mixed with varying amounts of graphite were used. The reaction products after burning these samples were identified by X-ray diffraction analysis. It can be shown, in good agreement with thermodynamic calculations, that under these conditions carbides are formed of the elements of groups IV-VI of the periodic table whereas instable intermetallic carbides are formed in the case of elements of groups VII and VIII. For studying the influence of thermochemical reactions on spectral line intensities, mixtures of several elements and their compounds in a graphite matrix were burnt and the intensities of suitable spectral lines measured. It was found that the line intensity of the sample components strongly correspond with thermodynamically favoured chemical reactions.