On the Problem of the Crystal Structures of Metals and Non-metals

<正>In 1926, Hume-Rothery noticed that there were regularities in the occurrance of the crystal stru-ctures in the alloys in terms of the average number of valence electrons per atom(called electron concentration,e/a). The b.c.cubic β phases occured close to an electron-atom ratio of 3/2, the c.p.hexagonul ∈ phases at 7/4 etc. In 1934, Jones accounted for these observations in terms of the relationships resulting from the interaction of Fermi Surface and Brillouin Zone boundaries, It was shown that the α、β、&、γ phases limits occured sometimes after contact of appropriate Brillouin Zone planes by the Fermi Surface. Hume-Rotherys realization of the importance of electron concentration in controlling the composition limits of certain metallic phases and Jones interpretation of this in terms of the Bloch theory of metals set a stage which has remained laryely unchanged for nearly 50 years o Both Hume-Rotherys rule and Jones interpretation are not vulid for all the metallic elements in the periodic Table