Search results for "Laves phase"
showing 3 items of 3 documents
High-pressure phases, vibrational properties, and electronic structure ofNe(He)2andAr(He)2: A first-principles study
2009
We have carried out a comprehensive first-principles study of the energetic, structural, and electronic properties of solid rare-gas RG-helium binary compounds, in particular, NeHe2 and ArHe2, under pressure and at temperatures within the range of 0T2000 K. Our approach is based on density-functional theory and the generalized gradient approximation for the exchange-correlation energy; we rely on total Helmholtz freeenergy calculations performed within the quasiharmonic approximation for most of our analysis. In NeHe2, we find that at pressures of around 20 GPa the system stabilizes in the MgZn2 Laves structure, in accordance to what was suggested in previous experimental investigations. In…
Preparation and structural analysis of Fe2+xTi1−x thin films in the C14 Laves phase stability range
2002
Abstract We report the epitaxial growth of single phase (0 0 1)-oriented thin films of Fe2+xTi1−x in the C14 Laves phase stability range using molecular beam epitaxy (MBE). The growth was studied by reflection high-energy electron diffraction (RHEED) and X-ray diffraction (XRD). The onset temperature for epitaxial growth and the temperature range for improved crystalline coherence were identified. From X-ray reflectometry analysis the rms roughness was estimated to 0.5 nm for typical film thicknesses of 22 nm. As revealed by scanning tunneling microscopy (STM), this roughness is discrete and due to step edges corresponding to the full c-axis length of Fe2Ti. The epitaxial growth implies an …
The titanium–iron–antimony ternary system and the crystal and electronic structure of the interstitial compound Ti5FeSb2
2003
Abstract Phase equilibria were established in the Ti–Fe–Sb ternary system below the TiSb2–FeSb section at 1070 K; the Sb–TiSb2–FeSb region was studied at 870 K. Investigation of the phase relations was based on X-ray diffraction experiments on arc-melted bulk alloys, which were annealed up to 350 h. Four ternary compounds were observed: TiFe1−xSb (0.64≤x≤0.70; defect TiNiSi-type), Ti1.18Fe0.57Sb (partially and statistically filled Ni2In-type), Ti1+xFeSb (−0.20≤x≤0.27; transformation from defect AlLiSi-type to the defect MnCu2Al-type), and new Ti5FexSb3−x (0.45≤x≤1.00; W5Si3-type). An extended solid solution up to about 10 at.% antimony was observed for the Laves phase Ti(Fe1−xSbx)2−y. Ti3Sb…