Materials Literature
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In the present work, we sought to improve our sparkle model for the calculation of lanthanide complexes, SMLC,in various ways: (i) inclusion of the europium atomic mass, (ii) reparametrization of the model within AM1 from a new response function including all distances of the coordination polyhedron for tris(acetylace…
A simple criterion to identify potential phase‐change materials is developed using density functional theory. These compounds rely on the switching between an amorphous and a crystalline state. Here it is demonstrated that suitable alloys have an average valence electron number larger than 4.1 and show p‐electron bond…
The fabrication of carbon nanotubes (CNTs) with controlled cross‐sectional shapes is reported for the first time. Anodic porous alumina with triangular openings is used as a template for the chemical vapor deposition synthesis of the CNTs with triangular cross‐sections (see Figure). The CNTs can be applied to the fabr…
Several experimental methodologies exist for measuring volatilities; however, results show great dispersion and sometimes lack of agreement between different methods. The aim of our study was to compare the performance of three static headspace methods (vapor phase calibration, VPC; phase ratio variation, PRV; and liq…
Zinc meso -tetraphenylporphyrin (ZnTPP) is known to have a relatively slow S 2 → S 1 internal conversion rate, (1−3 ps) -1, so that electron transfer from S 2 to a nearby acceptor is possible. We have synthesized two zinc porphyrins in which a pyromellitimide (PI) acceptor is attached to the para position of a meso -p…
We have implemented a set of Embedded Atom Method (EAM) potentials for simulation of Fe-Cr alloys. The functions for the pure elements were fitted to the respective elastic constants, vacancy formation energy, and thermal expansion coefficients. For Cr, properties of the paramagnetic state were applied, providing a po…
The novel mononuclear complex PPh(4)-mer-[Fe(III)(bpca)(3)(CN)(3)].H(2)O (1) [PPh(4)(+) = tetraphenylphosphonium cation and bpca = bis(2-pyridylcarbonyl)amidate anion] and ladder-like chain compound [[Fe(III)(bpca)(micro-CN)(3)Mn(II)(H(2)O)(3)] [Fe(III)(bpca)(CN)(3)]].3H(2)O (2) have been prepared and characterized by…
Point defects on oxide surfaces are presumed to be preferential nucleation sites for supported metal clusters. Under typical growth conditions, dimers constitute the first step in island nucleation. First-principles calculations on the formation of Pd dimers on regular and defect sites of the MgO(100) surface show tha…
In nanotube‐based electronics, Al 2 O 3 nanotubes will play a very important role. A method is reported that yields nanotubes with controllable, uniform wall thickness. The Figure represents the stage of the synthesis in which ZnO nanowires synthesized on a thick polycrystalline ZnO layer on a Si substrate have been c…
The preparation of ordered arrays of metal hollow spheres via colloidal crystal templating is reported. A seeded growth technique for metal coatings on isolated colloids in solution and a confined template‐directed synthesis method for metal patterning were combined. The polymer colloidal crystal template was prepared…
Multimodal atomic force microscopy (AFM) was used to map charge transfer properties in correlation to the molecular superstructure of poly(ethyldioxythiophene)–poly(styrenesulfonic acid) (see Figure). The lamellar domains of the polymer blend are indicated by phase shifts. Efficient charge injection occurs when lamell…
The poly(3,4-ethylenedioxythiophene) (PEDOT) films prepared in an aqueous sodium dodecyl sulfate and lithium tetrafluoroborate electrolyte solution were investigated. It was shown that the PEDOT films prepared in this medium exhibit novel electrochemical and optical properties. Cyclic voltammetric results indicate tha…
The effect of nanoconfinement on the glass transition temperature T(g) in thin polymer films is studied as a function of added small-molecule diluent or plasticizer. The decrease [increase] in T(g) found in nanoconfined, neat polystyrene [poly(2-vinyl pyridine)] is suppressed by added diluent, with 13-20 nm thick poly…
The problem of finding what direction cracks should move is not completely solved. A commonly accepted way to predict crack directions is by computing the density of elastic potential energy stored well away from the crack tip, and finding a direction of crack motion to maximize the consumption of this energy. I provi…
The remarkable transport properties of carbon nanotubes (NTs) are determined by their unique electronic structure (1). The electronic states of a NT form one-dimensional electron and hole subbands which, in general, are separated by an energy gap (2,3). States near the energy gap are predicted to have a large orbital…
The Budd-Vannimenus theorem is modified to apply to superconductors in the Meissner state. The obtained identity links the surface value of the electrostatic potential to the density of free energy at the surface which allows one to evaluate the electrostatic potential observed via the capacitive pickup without the ex…
The electrostatic potential close to the surface of superconductors in the Meissner state is discussed. We show that beside the Bernoulli potential, the quasiparticle screening, and the thermodynamic contribution due to Rickayzen, there is a non-local contribution which is large for both type-I and weak type-II superc…
We have employed first-principles electronic structure calculations to examine the hypothetical (but plausible) oxide spinel, LiCr2O4 with the d^{2.5} electronic configuration. The cell (cubic) and internal (oxygen position) structural parameters have been obtained for this compound through structural relaxation in th…
In this work a possible realizations of a uniaxial variant of left-handed material (LHM) at microwaves is considered. The meta-material has some features of the known structure studied by the group of D. Smith in 2001, however in the present structure a lattice of parallel wires and a lattice of artificial magnetic re…
An application of the radiolysis method using X-ray synchrotron beam is developed as a novel approach to the synthesis of metal-organic films with controlled shapes and thickness. We demonstrate that a Langmuir monolayer deposited onto a silver ion-containing subphase, irradiated by an incident beam impinging below th…