Materials Literature
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The temperature and pressure dependence of the photoluminescence from ZnS:Mn2+, ZnS:Cu2+, and ZnS:Eu2+ nanocrystals were investigated in the temperature range from 10 to 300 K and under hydrostatic pressure up to 6 GPa at room temperature. The orange emission (590 nm) from the T14-6A1 transition of Mn2+ ions, the gree…
Abstract Aluminum‐borate‐whiskers‐reinforced bismaleimide (BMI/Al 18 B 4 O 33 ) composites were prepared, and the mechanical and thermal properties were investigated. Results show that the coupling agent used for surface treatment of whiskers has a great effect on the properties of these materials. Composites containi…
In the presence of surfactant, potassium stearate, quantum-confined InP nanocrystals (NCs) were hydrothermally synthesized in aqueous ammonia. Powder x-ray diffraction (XRD) patterns give the zinc blende phase of InP with lattice constant a=5.8377±8×10−4 Å. Transmission electron microscopy (TEM) micrographs show that…
This paper explores the mechanism of bending with kinking of a long single-walled carbon nanotube under pure bending with moderate bending angles. The prebuckling response was modeled using the existing continuum mechanics theory accounting for the ovalization of the cross section. The post-buckling behavior was chara…
The origin of the nonexponential relaxation of silver ions in the crystalline ion conductor ${\mathrm{Ag}}_{7}{\mathrm{P}}_{3}{\mathrm{S}}_{11}$ is analyzed by comparing appropriate two-time and three-time ${}^{109}\mathrm{Ag}$ NMR correlation functions. The nonexponentiality is due to a rate distribution, i.e., dynam…
The mechanical properties—Young’s modulus (E) and hardness (H)—of diamond-like carbon (DLC) thin films deposited on p2+ Si (100) by filtered cathodic vacuum arc with different substrate bias voltage have been studied by nanoindentation measurement, where the substrate effect is included. Their intrinsic properties [in…
Octahedral and hexahedral diamond particles in the size range 4−450 μm were formed at temperatures of 400−600 °C by reduction of dense carbon dioxide with metallic lithium and potassium, respectively. The micro-Raman spectrum analysis shows that typical particles exhibit a sharp peak at 1332 cm -1, which is the charac…
The kinetics of oxygen removal from CeO2 were investigated using thermogravimetric analysis, at high temperatures, under a reducing atmosphere of Ar–6%H2. A chemical diffusivity model was developed that takes into account the composition dependence of both the pre-exponential factor and the activation energy. In this…
Raman and infrared reflection spectroscopies provide us information on electronic properties in polar semiconductors. In the present work, we have employed a dielectric function including the LO phonon damping in addition to the TO phonon damping and free carrier damping, and analyzed observed spectra of n-type 4H–SiC…
Correlation between the size-enhanced Stokes shift and the size-enlarged band gap expansion of porous silicon has been derived, which allows us to discriminate the effect of electron-phonon coupling from the effect of crystal binding on the blueshift in photoemission and photoabsorption of nanosolid silicon. Matching…
Thermoelectric properties of layered oxyselenides La1−xSrxCuOSe (x=0.00 to 0.20) were investigated to evaluate the potential as thermoelectric material. Temperature dependence of the electrical conductivity and Seebeck coefficient measured in a temperature range of 373 to 673 K indicated that nondoped LaCuOSe was a p-…
Microstructure and origin of the orange photoluminescence (PL) band of visible luminescing spark-processed germanium (sp-Ge) has been studied using simultaneous micro-Raman and -PL spectroscopy and scanning electron microscope. Instability of the sp-Ge film to energetic electron beams (⩾5 keV) during SEM measurements…
High pressure Raman scattering and x-ray diffraction studies of the molybdate ${\mathrm{Sc}}_{2}({\mathrm{MoO}}_{4}{)}_{3}$ are presented. A sequence of changing symmetry effects is observed through two structural phase transitions ending up with an amorphous state. The observed two structural phase transformations ar…
A CaF2:Er3+ single crystal was grown by the Tammann–Stober method. The potential of this material as a laser crystal for 1530 nm emission was established by quantitative analysis of the optical absorption and emission spectra. Assuming the tetragonal symmetry of the Er3+ sites, the Bkq crystal field parameters, Racah…
${\mathrm{CoS}}_{2}$ has recently been predicted to be highly spin-polarized, but very little is known about its magnetotransport properties. We find that this system exhibits a large anomaly in the resistivity at the Curie temperature ${(T}_{C}),$ which shows a pronounced shift with applied field, resulting in negati…
Inorganic multilayer films and hollow shells with pillared architectures have been fabricated layer-by-layer on spherical poly(methyl methacrylate) (PMMA) templates as well as flat substrates through the electrostatic self-assembly technique. Positively charged polyoxocations of aluminum Keggin ions were employed both…
Dielectric loss spectra at both ambient and elevated pressure are presented for propylene glycol (PG), dipropylene glycol, and tripropylene glycol. While in previous literature the excess wing (EW) was observed only for PG, we show herein that under high pressure an EW (coexistent with a secondary \ensuremath{\beta} r…
The present article deals with the optimized processing conditions leading to the highest density of Si nanoclusters which play the role of sensitizing centers for the nearby Er ions within a silica matrix. The layers were obtained by reactive magnetron sputtering under a plasma of Ar mixed to different rates of hydro…
The structure and folding of dihydrofolate reductase (DHFR) from Escherichia coli and the mutant G121V-DHFR, in which glycine 121 in the exterior FG loop was replaced with valine, were studied by molecular dynamics simulations and CD and fluorescence spectroscopy. The importance of residue 121 for the chemical step du…
We have investigated the electronic structure of Zn1−xMxO (M: 3d transition metal) by x-ray absorption spectroscopy. Using configuration–interaction cluster-model analyses, electronic structure parameters have been deduced and their chemical trend is discussed. Results show that the p–d exchange constant Nβ is negativ…