Materials Literature
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In this review article we briefly summarize the main experimental properties of (III,Mn)V ferromagnets and outline several different but related approaches that have been explored in an effort to gain insight into these materials. The main body of the paper deals with the development of the semi-phenomenological model…
In this paper we review the latest achievements of density functional theory in understanding the physics of diluted magnetic semiconductors. We focus on transition metal doped III-V semiconductors, which show spontaneous ferromagnetic order at relatively high temperature and good structural compatibility with existin…
Mixed-valence perovskite manganites (Re 1- x A x MnO 3 where Re = rare earth, A = alkaline earth) provide a unique opportunity to study the relationships between the structure and the magnetotransport properties due to an interplay among charge carriers, magnetic coupling, orbital ordering and structural distortion. T…
Supramolecular complex formation imparts stability and substrate selectivity to a simple manganese-porphyrin-based epoxidation catalyst. Lewis acid/Lewis base directed assembly was used to encapsulate the epoxidation catalyst within a supramolecular square structure to form an enzyme-like catalyst system. The "molecul…
Insight into the location, state, and function of a promoter in heterogeneous catalysis was obtained through atomic-resolution in situ transmission electron microscopy. In the most active ruthenium catalyst for ammonia synthesis known so far, the barium promoter is shown to be located in two different phases in the ca…
We describe preparation and magnetic properties of an organic pi-conjugated polymer with very large magnetic moment and magnetic order at low temperatures. The polymer is designed with a large density of cross-links and alternating connectivity of radical modules with unequal spin quantum numbers (S), macrocyclic S =…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTModeling the Barrier Properties of Polymer-Layered Silicate NanocompositesR. K. BharadwajView Author Information Avery Research Center, 2900 Bradley Street, Pasadena, California 91107 Cite this: Macromolecules 2001, 34, 26, 9189–9192Publication Date (Web):November 16, 2001Publi…
Femtosecond x-ray and visible pulses were used to probe structural and electronic dynamics during an optically driven, solid-solid phase transition in VO(2). For high interband electronic excitation (approximately 5 x 10(21) cm(-3)), a subpicosecond transformation into the high-T, rutile phase of the material is obser…
Thin films of composite germanium/silicon (Ge/Si) were prepared by pulsed laser ablation alternately on Ge and Si materials on a rotary target, followed by vacuum deposition of the ablated materials on an ultraclean glass substrate. X-ray diffraction and atomic force microscopy phase analysis confirmed that the film s…
The heterogeneous catalytic systems realized by alkaline earth oxides are successfully applicable to the highly efficient intramolecular Tishchenko lactonization of o-phthalaldehyde to phthalide.
In binary mixtures composed of homologues from a series derived from 4-alkoxybiphenyl- 4′-carboxylic acid exhibiting ferroelectric (FE) and antiferroelectric (AF) phases, a re-entrant FE phase may be induced in a certain concentration region, which is miscible with the SmC* phase. Dielectric spectroscopy study reveale…
The transfer of continuous-relief diffractive structures from resist into diamond by use of direct-write electron-beam lithography followed by dry etching in an inductively coupled plasma is demonstrated. The gases used for the diamond etching are O(2) and Ar. The chemical-vapor-deposited diamond substrate is of optic…
We report a study of the isotropic–nematic (I–N) transition in fluids of molecules interacting through the hard Gaussian overlap (HGO) model. This model is computationally simple and shears some similarities with the widely used hard ellipsoid (HE) fluid. The I–N coexistence properties of HGO fluids have been accurate…
Erbium doped Al2O3 films with concentrations up to 6×1020 Er cm−3 have been prepared in a single step process by pulsed-laser deposition. Alternate ablation of Al2O3 and Er targets has been used to control the in-depth distribution and in-plane concentration of Er3+ ions independently. The characteristic Er3+ photolum…
The solution structure of DsrC, an archaeal homologue of the gamma subunit of dissimilatory sulfite reductase, has been determined by NMR spectroscopy. This 12.7-kDa protein from the hyperthermophilic archaeon Pyrobaculum aerophilum adopts a novel fold consisting of an orthogonal helical bundle with a beta hairpin alo…
Abstract The syntheses and characterization of linear silarylene‐siloxane‐diacetylene polymers 3a–c and their thermal conversion to crosslinked elastomeric materials 4a–c are discussed. Inclusion of the diacetylene unit required synthesis of an appropriate monomeric species. 1,4‐Bis(dimethylaminodimethylsilyl)butadiyn…
By using laser ablation on mixtures of transition metal cobalt and group-14 elements, binary alloy cluster anions were produced while no binary alloy cluster cations were detected, and the homocluster cations of group-14 elements appeared at very low abundance. The differences between clustering abilities of germanium…
The dynamic behavior of a holographic grating induced in a homeotropically aligned dye-doped liquid-crystal film is investigated. In the presence of an applied dc voltage, photoexcited azo dyes induce a photorefractive grating and then diffuse and are adsorbed onto cell substrates. The reorientation of liquid crystals…
Layered structures of cubic yttria-stabilized zirconia (YSZ) sandwiched between two layers of platinum/YSZ composites with the platinum concentration varying between 20 and 55 vol % were prepared. Large double-layer capacitances were obtained due to the presence of large three-dimensional electrode surface areas in th…
In earlier attempts to shift the substrate specificity of glutamate dehydrogenase (GDH) in favour of monocarboxylic amino-acid substrates, the active-site residues K89 and S380 were replaced by leucine and valine, respectively, which occupy corresponding positions in leucine dehydrogenase. In the GDH framework, howeve…