Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide system

Investigations of ternary mixed early transition metal-rich sulfide and phosphide systems resulted in the discovery of new structures and new phases. These investigations further increased our understanding of the relationships between structure and bonding in metal-rich systems.;A new series of Zr and Hf - group V transition metal - sulfur $kappa$-phases was synthesized and crystallographically characterized. When the group V transition metal was Nb or Ta, the unit cell volume was larger than any previously reported $kappa$-phase. The presence of adventitious oxygen was determined in two $kappa$-phases through a combination of neutron scattering and X-ray diffraction experiments.;A compound Hf$sb{10}$Ta$sb3$S$sb3$ was found to crystallize in a new-structure type which is similar to the known gamma brasses. This structure type is unique in that it is the only reported "stuffed" gamma-brass type structure. The metal components, Hf and Ta, are larger in size and more electropositive than the metals found in "normal" gamma brasses (e.g. Cu and Zn) and because of the larger metallic radii, sulfur can be incorporated into the structure where it plays an integral role in stabilizing this phase relative to others. X-ray single-crystal, X-ray powder and neutron powder refinements were performed on this structure.;A new structure was found in the ternary Nb-Zr-P system which has characteristics in common with many known early transition metal-rich sulfides, selenides, and phosphides. This structure has the simplest known interconnection of the basic building blocks known for this structural class. Anomalous scattering proved to be a powerful tool for differentiating between Zr and Nb in this structure when using Mo K$alpha$ X-radiation. The compounds ZrNbP and HfNbP were found to form in the space group Pnma with the simple Co$sb2$Si structure which is among the most common structures found for crystalline solid materials.;Solid solution compounds in the Ta-Nb-P, Ta-Zr-P, Nb-Zr-P, Hf-Nb-P, and Hf-Zr-S systems were crystallographically characterized. The resulting structural information corroborated ideas about bonding in metal-rich compounds which have been developed in our laboratory in recent years.