Stabilizing metastable and unstable phases of palladium, magnesium and zirconium.

摘要

The present studies of new phases involve theoretical calculations of the epitaxial Bain paths (EBP) of tetragonal palladium, magnesium and zirconium and attempted stabilizations of the phases found. At room temperature, Pd has a face-centered cubic ground state, while the ground states of Mg and Zr have hexagonal close-packed structures. The EBP calculations indicate that magnesium and zirconium have face-centered cubic metastable phases and Pd has a body-centered tetragonal unstable state with axial ratio c/a∼0.9. Low energy electron diffraction intensity analyses have determined that these phases can be stabilized by means of constrained epitaxial growth of ultrathin films on a W{lcub}001{rcub} substrate.