CF
C. Fang
24 records found
1
Authored
Nb12O29 is a 4d transition metal oxide that occurs in two forms with different symmetries, monoclinic (m) and orthorhombic (o). The monoclinic form has unusual magnetic properties; below a temperature of 12 K, it exhibits both metallic conductivity and antiferromagnetic ordering.
...
Here, we show a novel solid-solid-vapor (SSV) growth mechanism whereby epitaxial growth of heterogeneous semiconductor nanowires takes place by evaporation-induced cation exchange. During heating of PbSe-CdSe nanodumbbells inside a transmission electron microscope (TEM), we obser
...
A set of interatomic pair potentials is developed for ZnO based on the partially charged rigid ion model (PCRIM). The derivation of the potentials combines lattice inversion, empirical fitting, and ab initio energy surface fitting. We show that, 0 despite the low number of parame
...
The eta-1-M(6)C, gamma-M(23)C(6), and pi-M(11)C(2) phases (M = Cr, Mn and Fe) have complex cubic lattices with lattice parameters of approximately 1.0 nm. They belong to the CFCC-TmC family (complex face-centered cubic transition metal carbides), display a rich variety of crystal
...
Iron carbides play a crucial role in steel manufacturing and processing and to a large extent determine the physical properties of steel products. The modified embedded atom method (MEAM) in combination with Lee's Fe-C potential is a good candidate for molecular dynamics simulati
...
Fe2C plays a crucial role in the precipitation of iron carbides. Jack's structural models for epsilon-Fe2C, and non-stoichiometric epsilon-Fe2.4C, are analyzed using first-principles calculations. Several new configurations of epsilon-Fe2C with even higher stability are found. We
...
First-principles calculations were performed for the c-phases and other iron carbides/nitrides with hexagonal close-packed Fe sublattices. Although these nitrides/carbides have similar crystal structures, they exhibit different chemical and physical properties. Relative to alpha-
...
Multiphase steels utilising composite strengthening may be further strengthened via grain refinement or precipitation by the addition of microalloying elements. In this study a Nb microalloyed steel comprising martensite, bainite and retained austenite has been studied. By means
...
Although Fe(2)C and Fe(2)N are technologically important materials, the exact nature of the chemical bonding of C and N atoms and the related impact on the electronic properties are at present unclear. Here, results of first-principles electronic structure calculations for Fe(2)X
...
We demonstrate that electron irradiation of colloidal CdS nanorods carrying Au domains causes their evolution into AuS/Cd core/shell nanoparticles as a result of a concurrent chemical and morphological transformation. The shrinkage of the CdS nanorods and the growth of the Cd she
...
A systematic first-principles study was conducted on the stability of binary iron carbides. The calculations showed that all the binary iron carbides are unstable relative to the elemental solids (¿-Fe and graphite). Apart from a cubic Fe23C6 phase, the energetically most favorab
...
First-principles calculations were performed for the c-phases and other iron carbides/nitrides with hexagonal close-packed Fe sublattices. Although these nitrides/carbides have similar crystal structures, they exhibit different chemical and physical properties. Relative to alpha-
...
Surface energies of the distinct facets of nanocrystals are an important factor in the free energy and hence determine the nanocrystal morphology, chemical and physical properties, and even interparticle dipole interactions. Here we investigate the stability and atomic structure
...
First-principles' calculations of GGA and GGA - U type have been performed for gamma-Fe23C6, a complex iron carbide with 116 atom in the unit cell GGA results were found to be in better agreement with experimental data than GGA + U results Various occupancies for Wyckoff position
...
A long-standing challenge in physics is to understand why cementite is the predominant carbide in steel. Here we show that the prevalent formation of cementite can be explained only by considering its stability at elevated temperature. A systematic highly accurate quantum mechani
...