Abstract
The syntheses of new mono-carbonitrides of W and/or Mo, i.e., W(C, N), Mo(C, N) and (W, Mo)(C, N), which are thermodynamically unable to be generated by using nitrogen gas of normal pressure, have been succeeded by the authors by using CH4+NH3 mixed gas of normal pressure (normal-pressure method) and C powder+nitrogen gas of high pressure (high-pressure method). The formations of these mono-carbonitrides as well as of general compounds by those methods have been explained by applying traditional Ostwald's step rule and virtual-pressure concept for normal-pressure method, and Le Chatelier's principle for high-pressure method, respectively. These explanations, however, are based only on the macroscopic level, but not on the atomic level.
In this paper, we newly proposed atomic models for the formation process of W(C, N) in both normal- and high-pressure methods, mainly based on the previous experimental results. The models include the concepts of "nascent atoms" and "nitrogen molecular cluster in supercritical fluid", etc., respectively.
