Materials Literature
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Polarization-resolved magnetophotoluminescence spectroscopy is used to study exciton spin states in 40--80 \AA{} diameter chemically synthesized CdSe quantum dots (QDs) at temperatures $T=1.2--50\mathrm{K}.$ The spin polarization is found not to saturate in magnetic fields to 60 T and time-resolved studies indicate a…
Examination on the existence of the critical and primary crystallite size ( d c α ∼ 17 nm and d p = 50−55 nm) phenomena during θ- to α-phase transformation of the nanosized Al 2 O 3 powder was designed and conducted using two θ-Al 2 O 3 powders of different crystallite sizes. Due to the critical size, the size depende…
We explain the reduction of the thermal conductance below the predicted universal value observed by Schwab et al. [Nature (London) 404, 974 (2000)] in terms of the scattering of thermal phonons off surface roughness using a scalar model for the elastic waves. Our analysis shows that the thermal conductance depends on…
Crystallization is a unique process that occurs at the expense of entropy, including the conformational entropy of surface residues, which become ordered in crystal lattices during formation of crystal contacts. It could therefore be argued that epitopes free of amino acids with high conformational entropy are more th…
Nonblended poly(L-lactide) (PLLA) films having different molecular weights and nonblended poly(lactide) (PLA) films, enantiomeric blend films from PLLA and poly(D-lactide) (PDLA), and diastereoisomeric blend films of poly(DL-lactide) (PDLLA) with either PLLA or PDLA, having different L-lactide (LLA) contents (X(LLA)s)…
Complex materials are known to show two regions of ac electrical behavior. In the high-temperature/low-frequency domain, they show power-law frequency dependence of the conductivity known as ``universal dielectric response,'' or UDR, while at low temperatures/high frequencies they show ``nearly constant loss,'' or NCL…
Using the point-contact Andreev reflection technique, we have carried out a systematic study of the spin polarization in the colossal magnetoresistive manganite, ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$ (LSMO). Surprisingly, we observed a significant increase in the current spin polarization with the…
Combining scanning electron microscopy (SEM) and electron-beam-induced current (EBIC) imaging with transport measurements, it is shown that the current flowing across a two-terminal oxide-based capacitor-like structure is preferentially confined in areas localized at defects. As the thin-film device switches between t…
We present the computer simulation results of a chain of hard point particles with alternating masses interacting on its extremes with two thermal baths at different temperatures. We found that the system obeys Fourier's law at the thermodynamic limit. This result is against the actual belief that one dimensional syst…
We analyze a two-dimensional phase field model designed to describe the dynamics of crystalline grains. The phenomenological free energy is a functional of two order parameters. The first one reflects the orientational order, while the second reflects the predominantally local orientation of the crystal. We consider t…
We study electromagnetic waves scattering by a 2D photonic crystal made of a stack of diffraction gratings. In case where there are only two propagative modes in the crystal, we derive an explicit expression for the superior (resp. inferior) envelope of the reflected (resp. transmitted) energy.
Double perovskites ${\mathrm{Sr}}_{2}\mathrm{Fe}M{\mathrm{O}}_{6}$ $(M=\mathrm{Mo}$ and Re) exhibit significant colossal magnetoresistance even at room temperature due to the high Curie temperatures (419 and 401 K). However, such a high Curie temperature is puzzling, given the large separation between magnetic element…
Abstract Polypropylene (PP) constituted 30% of the collected material in a Swedish collection system for rigid plastic packaging waste. The PP fraction was however a complex mixture of grades with widely different properties. In order to enhance the rigidity of the recycled PP, modified grades were prepared by compoun…
Surface second harmonic generation was used to obtain approximate orientational distributions of the side chains and the adsorbed liquid crystal (LC) molecules on a rubbed side-chain polyimide surface. Both the side chains and the LC molecules appear to be well aligned in the rubbing direction but tilted away from the…
${}^{139}\mathrm{La}$ rf enhancement experiments are shown to be an excellent tool for detecting changes of the local magnetic anisotropy in colossal magnetoresistance manganites. Based on this, we discuss the possibility of orbital ordering in ferromagnetic (FM) ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mat…
Abstract Six kinds of aromatic poly(amic acid) films, the precursor of polyimides, were uniaxially drawn by constant loads during thermal curing with varying the final curing temperature and the load. The in‐plane birefringence (Δn) generated by uniaxial orientation of polyimide molecules in the film plane was investi…
Smectic blue phases ( BP(Sm)) are thermotropic liquid crystalline phases which exhibit both three-dimensional orientational order, such as classical blue phases, and smectic positional order. BP(Sm) appear as the three-dimensional counterpart of twist grain boundary phases. X-ray scattering and optical polarizing micr…
We have investigated the local structure and photoluminescence properties of ultrasmall Ge islands grown on Si(111) covered with SiO2. Scanning electron microscopy and transmission electron microscopy measurements show that the islands have a hemispherical shape, and depending on the growth temperature, can be either…
We have grown epitaxial (Ba0.5, Sr0.5)TiO3 (BST) thin films on Si with very thin yttria-stabilized zirconia (YSZ) buffer layer. The thin YSZ buffer layer affects the stress state of the epitaxial BST layer as well as the growth behavior of the BST layer, i.e., the degree of epitaxy. The epitaxial BST films grown on Si…
The excitonic properties of high-quality ZnO/Zn0.88Mg0.12O multiquantum wells grown by laser-molecular-beam epitaxy were investigated using temperature-dependent optical absorption spectra from 5 K to room temperature. The strength of exciton-longitudinal-optical (LO) -phonon coupling was deduced from the temperature…