High pressure – high temperature studies and reactivity of γ‐Mo2N and δ‐MoN

Abstract

AbstractA combination of high pressure – high temperature synthesis and laser‐heated diamond anvil cell experiments, using synchrotron X‐ray diffraction has been used to investigate the phases in the Mo2N–MoN system under these conditions. Under conditions of high nitrogen activity, δ‐MoN appears to be a limiting phase i.e. there is no evidence for formation of new compounds such as Mo3N4 or Mo3N5, that are encountered in the Zr–N, Hf–N or Ta–N systems. When γ‐Mo2N is heated or prepared under conditions of high N2 activity, δ‐MoN is formed. The results indicate (a ) that there is no stable cubic stoichiometric “γ‐MoN” phase formed even under conditions of high pressure – high temperature and high N2 activity, and (b ) that no solid solution is formed between γ‐Mo2N and δ‐MoN. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)