Materials Literature
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The study of $(1\ensuremath{-}x){\text{PbMg}}_{1/3}{\text{Nb}}_{2/3}{\text{O}}_{3}\text{\ensuremath{-}}x{\text{PbTiO}}_{3}$ (PMN-PT) single crystals where $x$ is 0, 0.09, 0.21, 0.28, 0.32, 0.35, and 0.38 was carried out with the use of x-ray, dielectric, and Raman scattering techniques in a wide temperature range. In…
Anomalous quantum Hall effects in single-layer and bilayer graphene are related with nontrivial topological properties of electron states (Berry phases $\ensuremath{\pi}$ and $2\ensuremath{\pi}$, respectively). It was known that the Atiyah-Singer index theorem guarantees, for the case of the single layer, existence of…
Please release me: Dumbbell-shaped rod amphiphiles self-assemble into hollow spheres (see picture) with gated nanopores in the shell. These pores undergo reversible transitions from the open state to the closed state upon heating, and are capable of entrapping the cargos with preservation of their hollow spherical str…
The beam transfer matrix, often called the $ABCD$ matrix, is a two-by-two matrix with unit determinant, and with three independent parameters. It is noted that this matrix cannot always be diagonalized. It can however be brought by rotation to a matrix with equal diagonal elements. This equi-diagonal matrix can then b…
A flexible multi-parameter exactly solvable model of potential profile, containing an arbitrary number of continuous smoothly shaped barriers and wells, both equal or unequal, characterized by finite values and continuous profiles of the potential and of its gradient, is presented. We demonstrate an influence of both…
Oxygen adsorption on reduced ${\mathrm{TiO}}_{2}(110)$ is investigated using temperature programed desorption and electron-stimulated desorption. At low temperatures, 2 ${\mathrm{O}}_{2}$ molecules can be chemisorbed in each oxygen vacancy. These molecules do not desorb upon annealing to 700 K. Instead, for $200\text{…
Nanostructured Co 3 O 4 −CeO 2 and CuO−CeO 2 catalysts with the specific surface areas exceeding 100 m 2 g −1 were synthesized by a surfactant-templated method. The catalytic performance of these catalysts was investigated using the total oxidation of CO and C 3 H 8 as model reactions. The results show that the Co 3 O…
Electronic state and the Verwey transition in magnetite (Fe_3O_4) are studied using a spinless three-band Hubbard model for 3d electrons on the B sites with the Hartree-Fock approximation and the exact diagonalisation method. Complex-orbital, e.g., 1/sqrt(2)[|zx> + i |yz>], ordered (COO) states having noncollinear orb…
Four new hybrids based on the Wells-Dawson polyoxometalate [P2W18O62](6-) (P2W18), ([Ag(bipy)]2[P2W18O62]).2[H2bipy].4H2O (1), ([Ag(bipy)]4[P2W18O62]).2[Hbipy](2), K[P2W18O62].2.5[H2bipy].2H2O (3), and [P2W18O62] 2.[H2bipy]4.[Hbipy]4 .3H2O (4), were hydrothermally synthesized and structurally characterized by routine…
3-Mercaptopropionic acid stabilized CdTe/CdS core/shell quantum dots (QDs) were prepared in an aqueous solution following the synthetic route of successive ion layer adsorption and reaction. The photoluminescence quantum yield of the CdTe QDs could reach 40%, from 8% of the bare core, via the control of the shell thic…
In accounting for the magnetic properties of discrete and extended compounds with unpaired spins, it is crucial to know the nature of their ground and low-lying excited states. In this review we surveyed quantum mechanical descriptions on how these states are affected by spin-orbit coupling and attempted to provide a…
First-principles theory was used to investigate the roles of bond topology and covalency in the phase stability and elastic strength of 5d transition-metal diborides, focusing on elements (M=W, Re, Os) that have among the lowest compressibilities of all metals. Among the phases studied, the ReB(2)-type structure exhib…
A theoretical study of the influence of pressure on the dielectric relaxation related with polaron tunneling and phonon assisted hopping in disordered solids is developed. The sign and absolute value of the migration volume, which is obtained by employing the present formulation, evidence about the nature of the relax…
This paper is concerned with the bending problem of micro- and nanobeams based on the Eringen nonlocal elasticity theory and Timoshenko beam theory. In the former theory, the small-scale effect is taken into consideration while the effect of transverse shear deformation is accounted for in the latter theory. The gover…
The dispersion functions for the refractive index and the extinction coefficient of single- and multiple-layer graphene oxide samples were measured by imaging spectroscopic ellipsometry in the wavelength range of 350−1000 nm and were compared to previously reported results measured by confocal microscopy. The dispersi…
Au nanoparticles are known to be a good catalyst or an effective promoter for a wide range of catalytic reactions. Bimetallic Au−Pd nanoparticles supported on activated carbon were synthesized following a two-step procedure: immobilization of Au sol onto activated carbon followed by immobilization of Pd(0). The cataly…
There are numerous examples of animals or plants that synthesize extracellular high-performance skeletal biocomposites consisting of a matrix reinforced by nano sized crystalline domains. Cellulose and chitin are classical examples of these reinforcing elements, which occur as whisker-like microfibrils that are biosyn…
The limiting steps of CO oxidation catalyzed by ceria via the Mars−van Krevelen reaction mechanism are identified and investigated by means of density functional theory calculations that account for the on-site Coulomb interaction via a Hubbard term (DFT+U). We address the adsorption of CO on the (111) and (110) surfa…
The variability of bird beak morphology reflects diverse foraging strategies. One such feeding mechanism in shorebirds involves surface tension-induced transport of prey in millimetric droplets: By repeatedly opening and closing its beak in a tweezering motion, the bird moves the drop from the tip of its beak to its m…
The current-voltage characteristics of a silicon nanochain is investigated. The nanochain is viewed as a superlattice structure of quantum dots (QDs), where silicon cores in a chain act as QDs while silicon dioxides covering the cores act as potential barriers. It is found that the whole nanochain structure can displa…