| 摘要 |
Mononitrides of the rare earth metals and of yttrium are prepared by nitriding rare earth or yttrium metal in massive form, the masses having been previously subjected to a surface hydriding, the process being similar to that disclosed in the parent Specification. The surface hydriding preferably takes place at a temperature starting from 350 DEG C. For small metal samples, and for large samples of yttrium and of the rare earth metals which have relatively high melting points, the hydriding and nitriding may take place in one stage in the presence of both hydrogen and nitrogen; for large samples, especially those of the rare earth metals which have relatively low melting points, for example lanthanum, the masses may first be subjected to surface hydriding in the presence of hydrogen alone and subsequently be subjected to nitriding in the presence of both hydrogen and nitrogen. After nitriding by either method, the masses may be crushed and subjected, if the nitriding is not complete, to further nitriding. |
