Materials Literature
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Abstract Unrestricted Hartree–Fock calcuations coupled with second‐order Møller–Plesset correlation correction were performed to study the structures and energetics of microlusters. For (BN) 2 , linear and rhombus forms are almost isoenergetic, whereas cyclic forms are preferable for (BN) 3 and (BN) 4 clusters. As a g…
In this paper, we report the use of extended coupled cluster functional of Arponen, Bishop, and co-workers to implement a stationary biorthogonal response approach. The objective of this is to calculate nonlinear molecular properties like hyperpolarizability, etc. in a more convenient way.
We have studied the structure of the ${\mathit{Q}}_{1}$ charge-density wave (CDW) in pure and Ta-doped ${\mathrm{NbSe}}_{3}$ as a function of temperature using high-resolution x-ray scattering. The CDW's phase-phase correlation lengths are much greater than the impurity spacing, and in pure crystals can be comparable…
The authors present experimental results which indicate that a Dy3+-doped Ga:La:S glass fibre amplifier may be operated efficiently at 1.3 µm with an optimum device length significantly shorter than a comparable Pr3+-doped glass fibre amplifier. Moreover, the efficiency exceeds that obtained from the Pr3+-doped ZBLAN…
A model for small helical carbon tubules is presented. A heptagon-pentagon defect in a perfect fullerene tubule, which is made up entirely of hexagons formed by nearest-neighbor carbon-carbon bonds, bends the tubule at a 30\ifmmode^\circ\else\textdegree\fi{} angle, which is the angle between the axes of the two halves…
Cadmium diselenite, CdSe 2 O 5 , consists of an octahedrally coordinated Cd atom and a diselenite group that acts as a bidentate ligand. Cadmium hydrogenselenite selenite, Cd 3 (HSeO 3 ) 2 (SeO 3 ) 2 , has seven- and six-coordinated Cd atoms and two different selenite groups: hydrogenselenite and selenite
For a two-dimensional electron gas (2DEG) with a nonabrupt edge electron-density profile, edge modes, analogous to the higher-multipole surface modes of a 3DEG, are found in addition to the regular edge plasmon. Several simple model edge density profiles are investigated. For a linear edge profile the integral equatio…
The temperature dependence of the spin-lattice relaxation time for 7 Li has been measured in a single crystal of LiNaSO 4 over the temperature range of 450 K–770 K. The result can be explained by a mechanism of vacancy diffusion. The activation energies for the hopping of Li + and Na + vacancies are estimated to be E…
The electronic subband structure of periodically n-type \ensuremath{\delta}-doped silicon is calculated self-consistently within the local-density approximation. Two types of energy levels are distinguished, one due to valleys transverse to the superlattice axis, and the other due to longitudinal valleys. Minibands, p…
It is often suggested that the rate of interdiffusion at semiconductor heterostructure interfaces may be strongly dependent on elastic strain in the structure. Experimental and theoretical results show that strain does not, and should not, affect interdiffusion.
Accurate values are reported for the dipole (μ) and quadrupole (Θ) moment, dipole (α) polarizability, and first (β) and second (γ) dipole hyperpolarizability of ozone. Electron correlation effects are accounted for via coupled cluster (CC) theory with double substitutions corrected for the effects of single and triple…
We present results of a first-principles molecular-dynamics study of structural, dynamical, and electronic properties of liquid Ge. In agreement with experiments, the electronic density of states shows that liquid Ge is metallic. However, an analysis of the electronic charge density, pair correlation function, and str…
Techniques for visualization and quantification of the latent electric charge image on dielectric materials have been developed using Pockels effect of a BSO (Bi12SiO20) single crystal, a charge coupled device camera recording system, and a computer image processing technique. The Pockels device of the BSO single crys…
A study of the optical properties of the layered compound ${\mathrm{TlInS}}_{2}$ is presented. Reflection spectra were measured at room temperature, in the energy region 1.5--6.2 eV. Transmission spectra were measured in the temperature range 10--290 K, in the energy region 1.5--3.5 eV. Two structures, at energy posit…
The chiral nematic phase aligned with its helical axis along one preferred direction, being parallel to the confining substrates, exhibits a linear electro-optic effect when an electric field is applied normally to the substrates. The effect is considered to be of flexoelectric origin. A sign reversal of the effect is…
Double-crystal and triple-axis x-ray diffractometry was used to characterize in detail the strain and composition of short period Si6Ge4, Si8Ge8, Si9Ge6, and Si17Ge2 strained-layer superlattices (SLSs), grown by molecular-beam epitaxy. Nominally strain-symmetrized superlattices, intended to be free standing from under…
A method for first-principles calculations of spectra of strongly correlated systems is proposed. The impurity-Anderson-model is solved with a many-electron trial wave function. The obtained eigenvalues and eigenfunctions are used for one-electron removal (or addition) Green's-functions calculations. All parameters of…
Semiempirical tight-binding electronic-energy-band structures of the following ${\mathrm{II}}_{3}$${\mathrm{V}}_{2}$ semiconductors are presented: ${\mathrm{Cd}}_{3}$${\mathrm{P}}_{2}$, ${\mathrm{Zn}}_{3}$${\mathrm{P}}_{2}$, ${\mathrm{Cd}}_{3}$${\mathrm{As}}_{2}$, and ${\mathrm{Zn}}_{3}$${\mathrm{As}}_{2}$. The zinc-b…
Interconnects are susceptible to solid diffusion under residual stress, electric current, and elevated temperature. As atoms diffuse, voids nucleate, drift, and enlarge. At some point, the voids of rounded shape can collapse to narrow slits and sever the interconnects. The fatal slits are often found to be transgranul…
For what is to our knowledge the first time, electric-field-induced optical second-harmonic generation (SHG) is studied at the Si-SiO(2) interface by the use of a metal-oxide-semiconductor (MOS) structure. The crystallographic anisotropy of this phenomenon is studied for MOS structures. Experimental results indicate t…