XAFS STUDY OF SOME TITANIUM-SILICON AND GERMANIUM COMPOUNDS

It has been shown that, across the full range of Si-Ge alloy compositions, C54 Ti(SiyGe1-y)2 will form from the reaction of Ti with SixGe1-x. An increase in the silicon fraction (i.e., y>x)was seen with the formation of Titanium Germanosilicide which may be due, in part, to the relative diffusion rates of Si and Ge in Ti. In C54 Ti(SiyGe1-y)2 the Si and Ge atoms occupy sites equivalent to the Si in C54 TiSi2. Within error, these atoms form shells about the Ti atoms, with Si and Ge occupancies indicative of the net Si and Ge atomic percents. The radial distances of the shells vary linearly, within error, between those of C54 TiSi2 and C54 TiGe2. The ability to vary the shell distances (and thus vary the lattice constants) of C54 Ti(SiyGe1-y)2 by varying Si and Ge content will prove useful in applications where lattice matching and epitaxy are of importance.