Materials Literature
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The microstructure of segmented block copoly(ether esters) composed of poly(tetramethylene oxide) (PTMO) “soft” blocks and poly(butylene terephthalate) (PBT) “hard” blocks was investigated. A variety of analytical techniques, including 13 C solid-state NMR, infrared spectroscopy, dynamical mechanical analysis, dielect…
STM spectroscopy on the organic superconductor $\ensuremath{\kappa}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}\mathrm{Cu}(\mathrm{NCS}{)}_{2}$ has been performed in the superconducting state with the use of single crystals. The anisotropy of the superconducting gap has been investigated both on the $…
The recently-discovered MgB2 super-conductor has a transition temperature Tc approaching 40K, placing it intermediate between the families of low and high temperature super-conductors (LTS and HTS). In practical applications, super-conductors are permeated by quantised magnetic flux vortices, and when a current flows…
A theory for spin and lattice couplings to the electronic states in high-T$_C$ oxides is presented, with HgBa$_2$CuO$_4$ as an example. A simple analytical model suggests that the barrel band is sensitive to potential perturbations with long-range Fourier components, and that gaps can be opened at the Fermi energy. Th…
The first direct evidence that Ti atoms are not equally distributed in the 12 crystallographically independent T sites of the MFI framework is presented on the basis of neutron diffraction data collected at the HRPD instrument of the ISIS pulsed neutron source. We found strong evidence indicating that T6, T7, and T11…
We have used transmission ellipsometry to perform a comprehensive study of the glass transition temperature T(g) of freely standing polystyrene films. Six molecular weights M(w), ranging from 575 x 10(3) to 9100 x 10(3), were used in the study. For each M(w) value, large reductions in T(g) (as much as 80 degrees C bel…
We study the formulation of bond-orientational order in an arbitrary two-dimensional geometry. We find that bond-orientational order is properly formulated within the framework of differential geometry with torsion. The torsion reflects the intrinsic frustration for two-dimensional crystals with arbitrary geometry. Wi…
We report an epitaxial growth of LCMO (La2/3Ca1/3MnO3) film on Si by using a highly conducting diffusion barrier layer of TiN. In order to achieve epitaxial growth of LCMO films, MgO, and SrTiO3 films were used as intermediate layers between LCMO and TiN layers. The results have indicated that the properties of LCMO f…
First-principles total energy calculations of the 2-nm clusters seen in high-perfection Al (72)Ni(20)Co(8) decagonal quasicrystals demonstrate that chemical ordering between Al and transition metals in the central ring is energetically highly favorable. The chemical ordering introduces extensive structure relaxation a…
Incorporation of CdSe quantum dots into a thin (<1 μm) surface shell of polymer microspheres (R∼2–4 μm) is achieved. The room-temperature emission spectra of single, hollow microcavities show several, spectrally well-separated cavity modes in the red-orange spectral range which have been assigned to high-Q whis…
Using exact enumeration, conformational properties of a surface-interacting long flexible polymer chain are determined in a two-dimensional poor solvent where the possibility of collapse in bulk exists. A model of a self-attracting self-avoiding walk (SASAW) on a square lattice is considered and up to 28 steps in seri…
We experimentally demonstrate the production of nanoparticles by laser ablation of microparticles entrained at high density in a flowing aerosol. The currently measured production rate of 20 grams per hour could be scaled to industrially useful rates. We have characterized the size distribution of particles and found…
CaBi 4 Ti 4 O 15 (CBTi144) thin films were prepared by spin coating a precursor solution of metal alkoxides. As-deposited thin films began crystallization below 550 °C and reached full crystallinity of a single phase of layered perovskite at 650 °C via rapid thermal annealing in oxygen. The 650 °C annealed CBTi144 thi…
Nanosized La0.7Sr0.3MnO3/Pr0.5Sr0.5MnO3 (LSMO1−xPSMOx) ceramic composites are prepared using solid-sate sintering. Their microstructural, electro- and magnetotransport properties are characterized by means of various techniques. It is found that the antiferromagnetic/ferromagnetic coupling between PSMO/LSMO at low tem…
Pores in GaAs in the micrometer range and oriented in 〈111〉 directions have been observed during the anodization of GaAs in aqueous HCl electrolytes. A direct evidence of pores intersection is presented which is a very promising feature for three-dimensional micro- and nanostructuring of III–V compounds for the produc…
High-intensity synchrotron x-ray radioscopy was used to obtain real-time images of foaming metals, thus allowing the formation, growth, and decay of such systems to be studied. Bubble generation, foam coalescence and drainage of an aluminum-based alloy foam were investigated. Although the foaming process appears to be…
Variable-temperature atomic force microscopy, piezoresponse force microscopy (PFM), and scanning surface potential microscopy were combined to determine the temperature response of polarization and screening charge on BaTiO3(100) surfaces. The ferroelectric-domain induced surface corrugations and piezoelectric respons…
In this paper we demonstrate that convective Cahn-Hilliard models, describing phase separation of driven systems (e.g., faceting of growing thermodynamically unstable crystal surfaces), exhibit, with the increase of the driving force, a transition from the usual coarsening regime to a chaotic behavior without coarseni…
We have investigated the stress-stimulated luminescence (SSL) from ZnAl2O4:Mn. Two kinds of ZnAl2O4:Mn samples were synthesized at different reduction conditions to clarify the influence of the structure defects on the SSL property. The SSL intensity was found to be greatly increased by reducing ZnAl2O4:Mn at a high t…
Zirconium-doped indium oxide (ZIO) thin films (∼2000 Å thick) have been deposited by pulsed-laser deposition on glass substrates without a postdeposition anneal. The structural, electrical and optical properties of these films have been investigated as a function of substrate temperature and oxygen partial pressure du…