Defect Generation in Some Transition-Metal Silicides in Accommodating the Deviation from the Stoichiometric Compositions

Abstract

The changes in microstructure and defect structure of two different semiconducting transition-metal silicides, ReSi1.75 and Ru2Si3 with ternary alloying of substitutional elements with a valence electron number different from that of the constituent metal have been investigated in order to see if the crystal and defect structures of these silicides and thereby their physical properties can be controlled through defect engineering according to the valence electron counting rule. The Si vacancy concentration and its arrangement can be successfully controlled in ReSi1.75 while the relative magnitude of the metal and silicon subcell dimensions in the chimney-ladder structures can be successfully controlled in Ru2Si3.