Materials Literature
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A novel mean-field theory of photoinduced reorientation and optical anisotropy in liquid crystalline side-chain polymers is presented and compared with experiments. The reorientation mechanism is based on photoinduced $\mathrm{trans}\ensuremath{\leftrightarrow}\mathrm{cis}$ isomerization and a multidomain model of the…
Self-assembling of size, shape, and phase controlled nanocrystals into superlattices with translational and even orientational ordering is a new approach for engineering nanocrystal materials and devices. High purity tetrahedral nanocrystals of CoO, with edge lengths of $4.4\ifmmode\pm\else\textpm\fi{}0.2$ nm, were sy…
Thin films of binary mixtures that interact through isotropic forces and directionally specific "hydrogen bonding" are considered through Monte Carlo simulations. We show, in good agreement with experiment, that the single phase of these mixtures can be stabilized or destabilized on confinement. These results resolve…
We demonstrate the use of maximum entropy based deconvolution to reconstruct boron spatial distribution from the secondary ion mass spectrometry (SIMS) depth profiles on a system of variously spaced boron $δ$-layers grown in silicon. Sample independent response functions are obtained using a new method which reduces t…
In the example of the spherical $p$-spin model, we study the phase diagram of glassy systems in the presence of an attractive coupling with a quenched configuration. We find competition among two phases, separated by a coexistence line terminating in a critical point, as in ordinary first-order phase transitions. We a…
We develop a new real-space method which allows one to evaluate the Kubo-Greenwood formula for dc conductivity of independent electrons in a static potential. We apply it to a numerical study of propagation modes in three dimensional quasiperiodic systems. These modes are strikingly different from those of periodic on…
Temperature fields in microdevices made from silicon-on-insulator (SOI) wafers are strongly influenced by the lateral thermal conductivity of the silicon overlayer, which is diminished by phonon scattering on the layer boundaries. This study measures the thermal conductivity of single-crystal silicon layers in SOI sub…
We review recent experimental work falling under the broad classification of colossal magnetoresistance (CMR), which is magnetoresistance associated with a ferromagnetic-to-paramagnetic phase transition. The prototypical CMR compound is derived from the parent compound, perovskite . When hole doped at a concentration…
It was shown that in ultrafine‐grained nanostructured Cu processed by severe plastic deformation and subjected to cold rolling and annealing, the level and character of Young′s modulus anisotropy is significantly different from values corresponding to cold rolled and annealed coarse‐grained Cu. The crystallographic te…
The influence of a crystallographic texture (CT) on Dynamic Recrystallization (DRX) was investigated at T = 300℃ and 2.8 x 10 -3 s -1 in Mg–5.8% Zn–0.65% Zr in detail. It was shown that mechanics and kinetics of DRX are in strong dependence on location of basal planes. Initial texture effects recrystallized grain size…
The position operator (defined within the Schroedinger representation in the standard way) becomes meaningless when periodic boundary conditions are adopted for the wavefunction, as usual in condensed matter physics. We show how to define the position expectation value by means of a simple many-body operator acting on…
The effect of electrolyte concentration on the electropolymerization of pyrrole was investigated by studies of conductivity, tensile strength, and absorption spectra, etc., of polypyrrole films prepared from electrolyte aqueous solutions. The electrolyte salts used in the studies include sodium p-toluenesulfonate (TsO…
Fairly uniform spheres of crosslinked polystyrene (PS) and polymethyl methacrylate (PMMA), prepared by a particular emulsification process using SPG (Shirasu Porous Glass) membranes and subsequent suspension polymerization, were applied for immobilizing carriers of Glucoamylase (GluA). A mixture of monomers, solvents,…
Absolute viscosities of dilute solutions of poly(vinyl chloride) (PVC) in cyclohexanone and in its blends with xylene were determined at temperatures ranging from 5 to 50°C and in THF at 5–30°C. The simple Arrhenius reaction kinetics equation, used by Anrade to analyze the viscosity data of liquids and later by Moore…
Unvulcanized and dynamically vulcanized blends of isotactic polypropylene (PP) and butadiene styrene block copolymer (SBS) in the composition range of 10–40 wt % SBS were prepared by melt mixing in an internal mixer and evaluated for impact and tensile properties. Dynamic vulcanization of blends gave superior mechanic…
Blends of isotactic polypropylene (iPP) with the polyamide nylon-6 (N6), prepared by extrusion, were studied with a composition of up to 30% by weight polyamide. In the case of a 70/30 iPP/N6 blend, the influence of a compatibilizing agent based on polypropylene functionalized with maleic anhydride (PP-g-MA), with com…
The cloud point curves for polysulfone (PSf)/solvent/water systems were determined by a titration method. A small amount of water was needed to induce liquid-liquid demixing and the temperature effect was small. From numerical calculations, it was found that the binary interaction parameters for the PSf/solvent/water…
Dendrimers constitute a class of polymers with unique properties and applications resulting from the presence of internal voids and of a large number of functionalities on the surface. The development of a macromolecular chemistry within the cavities of dendrimers is illustrated here. Two examples of construction of s…
Metallic films are important in catalysis, magneto-optic storage media, and interconnects in microelectronics, and it is crucial to predict and control their morphologies. The evolution of a growing crystal is determined by the behavior of each individual atom, but technologically relevant structures have to be descri…
We review the effects of Coulomb correlation on the linear and non-linear optical properties of semiconductor quantum wires, with emphasis on recent results for the bound excitonic states. Our theoretical approach is based on generalized semiconductor Bloch equations, and allows full three-dimensional multisubband des…