ON THE BULK AND SURFACE ELECTRONIC STRUCTURE OF AMORPHOUS TRANSITION METALS

Abstract
Amorphous metals are characterized by the absence of a long range periodicity as well as the presence of a local disorder. The study of their electronic properties requires an understanding of the relation between the local disorder and the local electronic structure. In this work, we have carried out calculations on local density of d-states for bulk and surface of amorphous metals using moments method within tight-binding framework, in conjunction with various existing geometrical models. Our results show that the dominant factor governing the local density of states is the strength and shape of the first peak of the local radial distribution function. In the bulk where this local distribution has only small deviations from the average value, the density of states has a double peaked structure with peaks becoming sharper as the first maxima becomes stronger and peaked. As one goes to the surface, the decrease in the first coordination number leads to a merging tendency towards a single central peak. These calculations have been used to investigate some physical properties like the resistivity, thermoelectric power and the cohesive energy in amorphous materials.