Materials Literature
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We propose a hierarchical classification of kink species in dislocation cores which considers three sources of broken symmetry, host lattice structure, character of the dislocation, and core reconstruction effects. Kink multiplicity in bcc and diamond cubic lattices is examined and verified directly by atomistic calcu…
Computer simulations of the short-time, vibrational dynamics of the network-forming ionic melts, LaCl3 and ZnCl2, and of their mixtures with network-breaking alkali halides are described. In the mixtures, high frequency peaks in the vibrational density of states are shown to be describable in terms of the normal coord…
Efficient recording of polarization gratings in dye-doped liquid crystals is reported. By exploiting the effect of light-induced anchoring of the molecular director, it has been possible to write stable holographic gratings with a diffraction efficiency of 8% at a resolution of 1000 lines/mm. The required surface ener…
Barium ferrite (BaFe12O19) was elaborated and investigated in this work in terms of its capacitance-temperature characteristics. The curve taken at the fixed frequency of 1 kHz shows anomalous negative values of capacitance over the high-temperature regime. A complete analysis of this effect is carried out by performi…
A new technology utilizing a self-limiting mechanism for the Bi content is demonstrated for Bi2Sr2CuOy (2201) thin film growth by an atomic layer controlled molecular beam epitaxy. This technology is based on peculiar behavior of the Bi sticking coefficient that depends on the kinds of oxide thin films to be grown. Wh…
Vanadium dioxide thin films have been synthesized by pulsed laser deposition from pure vanadium metal targets. The electrical characteristics of these films were measured as a function of externally applied strain, based on three-point bend geometry. It is observed that strain significantly affects the resistance of t…
The room temperature thermal diffusivity evolution of electrochemically formed porous silicon as a function of the etching time is investigated. The measurements were carried out using the open-cell photoacoustic technique. The experimental data were analyzed using a composite two-layer model. The results obtained str…
Direct experimental evidence of half-metallic density of states (DOS) is observed by scanning tunneling spectroscopy on ferromagnetic ${\mathrm{La}}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{MnO}}_{3}$, which exhibits colossal magnetoresistance (CMR). Tunneling conductance data taken at 77 K, well below the Curie temperature $…
The spin dependence of the lifetime of electrons excited in ferromagnetic cobalt is measured directly in a femtosecond real-time experiment. Using time- and spin-resolved two photon photoemission, we show that the lifetime of majority-spin electrons at 1 eV above the Fermi energy is twice as long as that of minority-s…
The low-energy theory for single-wall carbon nanotubes including Coulomb interactions is derived and analyzed. It describes two fermion chains without interchain hopping but coupled in a specific way by the interaction. The strong-coupling properties are studied by bosonization, and consequences for experiments on sin…
We argue that long-range Coulomb forces convert an isolated $(N,N)$ armchair carbon nanotube into a strongly renormalized Luttinger liquid. At high temperatures, we find anomalous temperature dependences for the interaction and impurity contributions to the resistivity, and similar power-law dependences for the local…
The electromagnetic theory is used in order to characterize the polarization processes in glasses. The change in free energy owing to phase transformation of glasses in the presence of an electric field is . The analysis shows that the free energy may be reduced or enhanced by an electric field depending on the ratio…
The story of some not yet solved problems is presented, putting emphasis on the respective role of instrumentation, ab initio theories, phenomenology and simulations.
The damage spreading (DS) transitions of two one-dimensional stochastic cellular automata suggested by Grassberger (A and B) and the kinetic Ising model of Menyhárd (NEKIM) have been investigated on the level of kinks and spins. On the level of spins the parity conservation is not satisfied and therefore studying thes…
Flame retardation of polymeric materials for cables is becoming a statutory requirement due to governmental regulations to protect life and property from damages caused by fire. This and other factors such as the ever-increasing cost of existing flame retardants (FRs) have given rise to the search for better FRs. In t…
The reaction of poly(vinyl chloride) (PVC) in a plasticized formulation, with N-(2-amino ethyl)—3-aminopropyl trimethoxy silane yielded silane-grafted PVC that was crosslinked by a hydrolytic mechanism. The grafting of the aminosilane was carried out during processing on a two-roll mill, followed by compression moldin…
The grafting of poly(vinyl chloride) (PVC) by reactive aminosilane compounds, which make them moisture-curable, has been investigated. Plasticized poly-(vinyl chloride) has been successfully grafted with aminosilane during extrusion. The grafted polymer was crosslinked in the presence of moisture. Although the hydroly…
Fracture toughness of injection-molded PA6/PP blends compatibilized with SEBS-g-MA was studied using deeply double-edge notched tension (DDENT) specimens according to the essential work of fracture procedure. The fracture mechanical studies also included tensile impact tests on the DDENT specimens and characterization…
Bioartificial polymeric materials based on blends of dextran and poly(acrylic acid) were prepared in form of films and characterized in order to evaluate the miscibility of the natural component with the synthetic one. Films with different composition ratios were prepared by solution casting and analyzed by dynamic me…
Plastics that conduct electricity have been of intense interest both for technological applications and basic polymer science. In his Perspective, Scott discusses results reported in the same issue by [Lonergan][1] in which a conducting polymer has been used to fabricate a basic electronic device. Scott places this wo…