ELECTRONIC-STRUCTURE AND HYBRIDIZATION EFFECTS IN HUME-ROTHERY ALLOYSCONTAINING TRANSITION-ELEMENTS

We present a systematic study of the electronic structure of Al-based Hume-Rothery alloys containing transition elements performed with the use of the linear muffin-tin orbital in atomic-sphere approximation me thod. Our analysis focuses on the formation of the pseudogap at the Fe rmi level leading to the stability of materials containing transition- metal elements in small concentration. From the self-consistent calcul ated density of states, we observe a strong deviation from the two cla ssical limits: (a) the Friedel-Anderson virtual bond state's model and (b) the nearly-free-electron diffraction by some Bragg planes in the usual Hume-Rothery picture of simple metal alloys. Transition-metal at oms have a crucial role on electronic structure via the combined effec t of the sp-d hybridization and of a strong interaction between the Fe rmi surface and a predominant Brillouin zone.