Studies of pressure induced phase transformations of ZnS nanoparticles using diamond anvil cells and synchrotron radiation were carried out to 20.0 GPa. Nanoparticles initially in the zinc-blende and wurtzite phases both transformed to the NaCl phase under the application of pressure. The zinc-blende particles, which were of 2.8 nm size, and the wurtzite particles, which were of 25.3 nm size, t...

We develop a nucleation-based model to explain the formation of the wurtzite phase during the catalyzed growth of freestanding nanowires of zinc blende semiconductors. We show that in vapor-liquid-solid nanowire growth, nucleation generally occurs preferentially at the triple phase line. This entails major differences between zinc blende and wurtzite nuclei. Depending on the pertinent interface...

We report a new biphasic crystalline wurtzite/zinc-blende homostructure in gallium nitride nanowires. Cathodoluminescence was used to quantitatively measure the wurtzite and zinc-blende band gaps. High-resolution transmission electron microscopy was used to identify distinct wurtzite and zinc-blende crystalline phases within single nanowires through the use of selected area electron diffraction...

Large ('1000 atoms) supercell valence force-field simulations are used to investigate the nearest-neighbor bond-length distribution in relaxed tetrahedral ~zinc blende and wurtzite! and octahedral ~rocksalt! Ga12xInxN alloys. We find that, due to the rigidity of the octahedron, the distribution of each anion-cation bond length in rocksalt alloys has two contributions: unrelaxed bonds and relaxe...

The full-potential augmented plane wave plus local orbital method within density-functional theory is used to predict that MnBi in the zinc-blende structure is a true half-metallic ferromagnet with a magnetic moment of 4.000mB per formula unit. This contrasts with the zinc-blende phase of MnAs, which is only a nearly half-metallic ferromagnet. This half-metallic ferromagnetic behavior of zinc-b...

Bulk crystals of ZnS usually take the zinc blende structure. However, the vapor deposited one-dimensional ZnS nanostructures normally take the metastable wurtzite structure. This Letter investigates the conditions under which the formed phase can be controlled between zinc blende and wurtzite in nanomaterials synthesis. The formation of pure zinc blende structured ZnS nanobelts is related not o...

This paper describes the equilibrium morphologies of zinc sulfide nanoparticles in the wurtzite phase as a function of size, determined using ab initio Density Functional Theory (DFT) simulations and a shape-dependent thermodynamic model predicting the Gibbs free energy of a nanoparticle. We investigate the relative stabilities of a variety of nanoparticle shapes based on the wurtzite structure...

For the limitation of experimental methods in crystal characterization, in this study, the mechanical, thermodynamic and electronic properties of wurtzite and zinc-blende GaN crystals were investigated by first-principles calculations based on density functional theory. Firstly, bulk moduli, shear moduli, elastic moduli and Poisson's ratios of the two GaN polycrystals were calculated using Voig...

This study examined the local structural properties of CuI at low temperatures of 10-300 K by x-ray diffraction (XRD) and extended x-ray absorption fine structure (EXAFS) measurements at the Cu K edge. The XRD data were refined using two models, split (distorted zinc-blende structure) and non-split (zinc-blende structure), using a conventional Rietveld refinement combined with a maximum entropy...

The structure of the pseudo-binary mercury chalcogenide alloy HgSe0.7S0.3 has been studied by X-ray and neutron powder diffraction at pressures up to 8.5 GPa. A phase transition from the cubic zinc blende structure to the hexagonal cinnabar structure was observed at P ∼ 1 GPa. A phenomenological model of this reconstructive phase transition based on a displacement mechanism is proposed. Analysi...