Title

Phase stability in refractory metal silicides

Abstract

Refractory metal (RM) silicide phases are attractive as high temperature structural materials and at low temperature for microelectronic applications. While silicides can develop oxidation resistant SiO2 coatings, multiphase alloy designs are necessary to achieve satisfactory structural performance. The basis for the structural stability analysis is derived from the behavior in Mo-RM-Si-B and RM-Si-C systems. The observed alloying trends in ternary and higher order systems highlight the fundamental factors such as geometric rules and electronic factors that govern phase stability. Often, the drive to achieve a high packing density of metal and metalloid constituents yields a strict range of atomic size ratios of metal to metalloid that favors structural stability. Usually, silicides are stoichiometric, but there are cases with a homogeneity range where defect structures are important. By following the guidance offered by the geometric rule and electronic factors it has been possible to design new multiphase microstructures by systematically modifying the phase stability.

Document Type

Conference Proceeding

Keywords

Alloying, E/a, Silicides, Size effect, T 2

Publication Date

12-1-2005

Journal Title

TMS Annual Meeting

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