Die Systeme Nickel—Selen und Kobalt—Nickel-Selen

摘要

The Ni−Se system was investigated by X-ray and thermal analyses and from the results and from published data the Ni−Se phase diagram was constructed. The high temperature phase β-Ni3Se2decomposes peritectically at 785°C, the compound Ni6Se5peritectoidically at 647.5°C. The B8 (NiAs) phase Ni1−xSe has a congruent melting point at 53.5 at Se and 959°C and a maximum range of homogeneity between 50.5 at Se (785 °C) and 56.8 at Se (856 °C). NiSe2decomposes peritectically at 853 °C into Ni1−xSe and a Se-rich melt. Melts with more than 68.0 at Se exhibit above 856 °C a miscibility gap. X-ray investigations confirmed the existence of the four compounds α-Ni3Se2, Ni6Se5, Ni