Materials Literature
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The internal structure of PbSe nanocrystals was deduced using synchrotron X-ray photoemission spectroscopy for three different sizes of nanocrystals. The photoemission data revealed the layered structure of PbSe nanocrystals with the crystalline PbSe core surrounded by a nonstoichiometric Pb(1-x)Se shell, finally pass…
The CdS and CdS-Ag core-shell quantum dots (QDs) have been prepared. The nanostructures of the QDs were revealed by transmisson electron microscopy and absorption spectra, respectively. The third-order nonlinear optical properties of the core-shell QDs have been studied by using Z-scan technique with femtosecond pulse…
A facile and mild means of controllably preparing a series of single-crystalline alkaline-earth metal fluoride nanowires of reproducible shape and varying sizes (see figure) using a simple, room-temperature approach has been developed. This approach is based on the use of readily commercially available polycarbonate t…
Bubbles pushed through a quasi-two-dimensional channel self-organize into a variety of periodic lattices. The structures of these lattices correspond to local minima of the interfacial energy. The "flowing crystals" are long-lived metastable states, a small subset of possible local minima of confined quasi-two-dimensi…
Crystal structures, magnetic and thermodynamic properties of the spin-crossover compound tris(2-picolylamine)iron(II) dichloride (with 2-propanol solvent molecules) have been measured in the temperature range from 15 to 293 K. X-ray diffraction, SQUID, and calorimetric experiments all showed two first-order phase tran…
PbSe nanorods and branched nanorods are grown using binary Au–Fe3O4 nanoparticles as seeds. PbSe nucleates on the gold portion of the seed particle and grows anisotropically as one or more straight or branched nanorods. Seeding with binary particles has significant advantages over seeding with pure-metal particles. Th…
General, efficient and inexpensive methods for the synthesis of dendritic building blocks methyl 3',4'-dihydroxybiphenyl-4-carboxylate, 3',5'-dihydroxybiphenyl-4-carboxylate, and methyl 3',4',5'-trihydroxybiphenyl-4-carboxylate were elaborated. In all syntheses the major step involved an inexpensive Ni(II)-catalyzed S…
We present calculations of the nucleation barrier during crystallization in binary hard sphere mixtures under moderate degrees of supercooling using Monte Carlo simulations in the isothermal-isobaric semigrand ensemble in conjunction with an umbrella sampling technique. We study both additive and negatively nonadditiv…
Oxide-supported Au nanostructures are promising low-temperature oxidation catalysts. It is generally observed that Au supported on reducible oxides is more active than Au supported on irreducible oxides. Recent studies also suggest that cationic Au(delta+) is responsible for the unique Au/oxide catalytic activity, con…
The influence of post-sintering annealing on the dielectric properties of $\mathrm{Ca}{\mathrm{Cu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$ was investigated in the temperature range form $200\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}400\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. A dielectric peak featu…
Motivated by the recent discovery of the experimental possibility to obtain two-dimensional (2D) crystals and the permanent interest in carbon materials, we perform a theoretical investigation of the stability and electronic properties of 2D graphite (graphene) and also of some new similar carbonic structures. Using t…
In recent years, the formation of thin, well-ordered but complex surface oxides on late transition metals has been discovered. The driving force for this line of research has been the strong incentive to increase the partial pressure of oxygen from ultra-high vacuum to conditions more relevant for heterogeneous cataly…
We demonstrate the kinetic arrest of the first-order phase transition from the high-temperature antiferromagnetic state to the ferromagnetic ground state in zero and low applied magnetic fields, occurring within the experimental time scale in the magnetocaloric material ${\mathrm{Gd}}_{5}{\mathrm{Ge}}_{4}$. A magnetiz…
The present study describes a stabilization of single quantum dot (QD) micelles by a "hydrophobic" silica precursor and an extension of a silica layer to form a silica shell around the micelle using "amphiphilic" and "hydrophilic" silica precursors. The obtained product consists of approximately 92% single nanocrystal…
A high-pressure sliding plate rheometer was used to determine the effects of supercritical fluids and pressure on the viscosity of molten high-density polyethylene (HDPE). In this instrument, the shear strain, temperature, pressure, and gas concentration are all uniform, and a shear stress transducer senses the stress…
We analyse the statistical distribution function for the height fluctuations of brittle fracture surfaces using extensive experimental data sampled on widely different materials and geometries. We compare a direct measurement of the distribution to a new analysis based on the structure functions. For length scales $δ$…
Spin-dependent coherent quantum transport through carbon nanotubes (CNT) is studied theoretically within a tight-binding model and the Green's function partitioning technique. End-contacted metal/nanotube/metal systems are modelled and next studied in the magnetic context, i.e. either with ferromagnetic electrodes or…
The relaxor ferroelectric $({\mathrm{PbMn}}_{1∕3}{\mathrm{Nb}}_{2∕3}{\mathrm{O}}_{3}{)}_{1\ensuremath{-}x}({\mathrm{PbTiO}}_{3}{)}_{x}$, $x=0.1$ [PMN/PT (90/10)], is found to exhibit several regimes of complicated aging behavior. Just below the susceptibility peak there is a regime exhibiting rejuvenation but little m…
We have studied photoluminescence and resonant Raman scattering of single-walled carbon nanotubes (SWNTs) consisting of carbon-13 $({\mathrm{SW}}^{13}\mathrm{CNTs})$ synthesized from a small amount of isotopically modified ethanol. There was almost no change in the Raman spectra shape for ${\mathrm{SW}}^{13}\mathrm{CN…
Discotic liquid crystals can self-align to form one-dimensional semiconducting wires, many tens of microns long. In this letter, we describe the preparation of semiconducting films where the stacking direction of the disc-like molecules is perpendicular to the substrate surface. We present measurements of the charge c…