The role of zinc on the chemistry of complex intermetallic compounds

Combining experiments and electronic structure theory provides the framework to design and discover new families of complex intermetallic phases and to understand factors that stabilize both new and known phases. Using solid state synthesis and multiple structural determinations, ferromagnetic -Mn type Co8+xZn12–x was analyzed for their crystal and electronic structures. Inspection of the atomic arrangements of Co8+xZn12–x reveals that the Mn aristotype may be derived from an ordered defect, cubic Laves phase (MgCu2-type) structure. Structural optimization procedures using the Vienna Ab-initio Simulation Package (VASP) and starting from the undistorted, defect Laves phase structure achieved energy minimization at the observed -Mn structure type, a result which offers greater insights into the -Mn structure type and establishes a closer relationship with the corresponding -Mn structure (cI58). Continuously, our research moved on Zn-rich -brasses Co-Zn system which has a homogeneity range Co2+xZn11–yy–x including a small concentration of vacancies as the Co content increased as well as clear site preference of Co atoms in the structure. Inspired by the electronic structure calculated for Co2Zn11, substituting Pd atoms for Zn or Co atoms in the Co-Zn system leads to the discovery of a ferromagnetic ( erromagnetic) Co2.5Pd2.5Zn8 brass compound. To extend the research on Hume-Rothery phases, -brasses Fe-Pd-Zn system was also investigate to study the site preference of transition metals in Hume-Rothery phases. Additionally, establishing structure-property relationships for complex metal-rich materials, e.g., thermoelectric, magnetic and superconductors is related to both practical as well as fundamental issues. Cr22Sn24Zn72 and V23.3(1)Sn26.3(1)Zn68.4(1) crystallize in space