Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTTwo-Step Percolation in Polymer Blends Filled with Carbon BlackMing Qiu Zhang, Gang Yu, Han Min Zeng, Hai Bo Zhang, and Yan Hui HouView Author Information Materials Science Institute, Zhongshan University, Guangzhou 510275, P. R. Ch…
We point out that the existing experimental data of most manganese oxides show the {\sl frustrated} p-wave superconducting condensation in the ferromagnetic phase in the sense that the superconducting coherence is not long enough to cover the whole system. The superconducting state is similar to the $A_{1}$ state in s…
A novel, general Green's function technique for elastic spin-dependent transport calculations is presented, which (i) scales linearly with system size and (ii) allows straightforward application to general tight-binding Hamiltonians (spd in the present work). The method is applied to studies of conductance and giant m…
The work is devoted to investigation of the collective behavior of the regular rectangular lattices of the NiFe nanoparticles caused by the dipole-dipole interaction between them. The samples was prepared by the method of the electron lithography and consist of about 100000 particles of approximately 50 nm size. The m…
A nucleation method to form diamond on chemically pretreated silicon (111) surfaces is reported. The nucleation consisted of binding covalently 2,2-divinyladamantane molecules on the silicon substrate. Subsequently, low pressure diamond growth was performed via microwave plasma chemical vapor deposition in a tubular d…
We report zero-field muon spin rotation data in single crystals of ${\mathrm{La}}_{1.4}{\mathrm{Sr}}_{1.6}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}$ for $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}5--325\mathrm{K}$. The spin-lattice relaxation rate is spatially inhomogeneous below the 3D magnetic transition temperatu…
The effects of monovalent alkali metal substitution into the lanthanide sites in oxides are presented. We report structural features, magnetic and electrical properties of these materials for . The lattice symmetry of the samples is found to be rhombohedral. All the phases are ferromagnetic, with Curie temperatures st…
The near-edge x-ray absorption fine structures (NEXAFS) of hydrogenated diamond films and single-crystal diamond surfaces have been studied by recording the partial electron yield and the H+ and H− ion desorption yields as a function of photon energies around the C(1s) core level. It has been found that ion desorption…
Sb nanocrystals were formed in thin, thermally grown SiO2 layers using low-energy ion implantation followed by thermal annealing. These Sb nanocrystals have good size and position uniformity. Both the narrow as-implanted profile and the compressive strain that exists near the SiO2/Si interface supposedly contribute to…
The magnetoresistance of mechanically induced grain boundaries in La0.7Ca0.3MnO3 thin films is investigated. The grain boundaries are fabricated by a mechanical deformation of the LaAlO3 substrate prior to film deposition. During film deposition, the deformed substrate region induces some growth disorder in the film l…
High-quality (001) thin film La0.5Sr0.5CoO3−x (LSCO) has been prepared on (001) SrTiO3 substrates by pulsed laser deposition under different oxygen pressures with and without postannealing. C-axis expansion of the LSCO with reducing oxygen pressure was revealed. The electrical resistivity increased over five orders of…
A novel principle for cooling by adiabatic pressure application in the mixed crystalline compound Pr1−xLaxNiO3 is described and experimentally verified. Cooling occurs in the vicinity of the structural phase transition where the electronic ground state of the Pr3+ ions changes from a singlet to a doublet state. By pro…
Porous silicon (PS) with nondegrading photoluminescence (PL) was prepared by a novel method. For fresh samples, the PL peak intensity is 2--2.5 times stronger than that in normal PS. Upon exposing PS to ambient air, the PL intensity increases during the first four months and then saturates. No PL degradation is observ…
single crystals were grown by the laser floating zone method. Polarized Raman spectra were measured and interpreted consistently with the Pcmn crystal space group. Up to 16 Raman modes were identified and their symmetry assigned. The infrared optical constants of were determined from the analysis of the reflectance sp…
Reactions on surfaces play an important role in many technological applications. Since these processes are often rather complex, one tries to understand single steps of these complicated reactions by investigating simpler system. In particular the hydrogen dissociation on surfaces serves as such a model system. There…
Density functional theory (DFT) primarily provides a good description of the electronic structure. Thus, DFT primarily deals with length scales as those of a chemical bond, i.e. 10^-10 meter, and with time scales of the order of atomic vibrations, i.e. 10^-13 seconds. However, several interesting phenomena happen and/…
Knowledge of the atomic geometry of a surface is a prerequisite for any detailed understanding of the surface's electronic structure and chemical properties. Previous studies have convincingly demonstrated that density functional theory (DFT) yields accurate surface atomic geometries and that reliable predictions conc…
The electronic structure of finite-length armchair carbon nanotubes has been studied using several ab-initio and semi-empirical quantum computational techniques. The additional confinement of the electrons along the tube axis leads to the opening of a band-gap in short armchair tubes. The value of the band-gap decreas…
The lowest energy structures of ${\mathrm{Au}}_{n}$ ( $n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}38,55,75$) nanoclusters are obtained by unconstrained dynamical and genetic-symbiotic optimization methods, using a Gupta $n$-body potential. A set of amorphous structures, nearly degenerate in energy, are found…
Experimental observations of various deformation and fracture modes under compression of single multiwalled carbon nanotubes, obtained as a result of embedment within a polymeric film, are reported. Based on a combination of experimental measurements and the theory of elastic stability, the compressive strengths of th…