Interface stability of Ti(SiGe){sub 2} and SiGe alloys: Tie lines in the ternary equilibrium diagram
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States)
- IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (United States)
The C54 phases of TiSi{sub 2} and TiGe{sub 2} are known to be completely miscible, however, we have observed that thin films of C54 Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} are not stable in contact with Si{sub 1{minus}{ital x}}Ge{sub {ital x}} when {ital y}={ital x}. In this study it is shown that this interface instability can be related to the composition-dependent energetics that determine the Ti-Si-Ge ternary equilibrium diagram. Tie lines of the Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} to Si{sub 1{minus}{ital x}}Ge{sub {ital x}} system were calculated on the basis of classical thermodynamics. The calculations indicate that for C54 Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} to be stable in contact with Si{sub 1{minus}{ital x}}Ge{sub {ital x}} the compositions of the two phases must be such that {ital y}{lt}{ital x}. The specific compositions of the two phases in equilibrium depend on the temperature and the relative quantities of the two phases. The dynamics of the interface reactions of C54 Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} on Si{sub 1{minus}{ital x}}Ge{sub {ital x}} are related to the calculated tie lines, and the diffusion kinetics of the materials. Experimental results are presented that quantitatively support the model calculations. {copyright} {ital 1996 The American Physical Society.}
- DOE Contract Number:
- FG05-89ER45384
- OSTI ID:
- 285604
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 53, Issue 24; Other Information: PBD: Jun 1996
- Country of Publication:
- United States
- Language:
- English
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