par Decroly, Claude ;Ghodsi, Mehdi
Référence Journal of The Less-Common Metals, 6, 5, page (375-395)
Publication Publié, 1964-05
Article révisé par les pairs
Résumé : The reactions of germanium dioxide with iron and its oxides have been studied theoretically and experimentally.Thermodynamic calculations show that germanium dioxide is reducible to germanium monoxide by iron and ferrous oxide. Reduction by iron should be easy as the calculated equilibrium pressures of germanium monoxide are comparatively large for temperatures above 800°C. Reduction by ferrous oxide and magnetic oxide is also theoretically possible.Experiments have been made to study the kinetics of the reactions and their stoichiometry. Under vacuum, reduction of germanium dioxide to germanium monoxide by iron is rather rapid at temperatures in the vicinity of 1000°C. Under the same conditions, reduction by ferrous oxide is still possible but is slower than the reduction by iron. Reduction by iron in a current of argon is possible too but is also slower than the reduction under vacuum. In no cases did the reduction go to germanium element, germanium monoxide being rapidly transferred to the cooler part of the apparatus.X-ray studies have shown that in the case of the reduction of germanium dioxide by iron, there is formation of ferrous oxide and magnetic oxide since the beginning of the reduction, fact which is not observed in the case of the reduction of zinc oxide by iron.