Materials Literature
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Effects of Bi, Cr, and Fe doping on phase separation of ${\mathrm{La}}_{0.67}{\mathrm{Ca}}_{0.33}{\mathrm{MnO}}_{3}$ have been experimentally studied. As proved by the electron-spin resonance and neutron-diffraction studies, partial replacement of La by Bi causes the simultaneous occurrence of ferromagnetic (FM) phase…
Ar condensates in a porous Vycor glass with an average pore diameter of 10 nm have been studied by optical transmission. Cooling-heating cycles have been performed through the freezing and melting transition for samples with different fractional fillings. Freezing leads to a decrease of the transmission up to four ord…
We have studied the physical properties of epitaxial La0.67−xPrxCa0.33MnO3(LPCMO) (x=0.13, 0.20, 0.27) thin films under different type and degree of substrate induced biaxial strain. Films with thickness of 300, 600, and 1000 Å grown on crystalline NdGaO3 (negligible strain), LaAlO3 (compressive strain), and SrTiO3 (t…
A variety of single-wall carbon nanotube samples were tested in steady-state and time-resolved emission experiments, where it was found that chemical functionalization and different degrees of oxidation affect the emission behavior.
In this study, the electrical and magnetic properties of La1−xTexMnO3 (x=0.1, 0.15), which is a new material and shows good colossal magnetoresistance behavior, have been investigated. These compounds have rhombohedral structure. In this material, Te replaced a part of La ions, which induced the lattice cell constrict…
Density functional calculations show that the “magic” structures of titanium carbide nanoparticles display an unexpected high reactivity toward CO, NH3, and H2O when compared to the bulk TiC(001) surface. In spite of the large C/Ti ratio in Ti8C12, our results show that the bulk surface is much more tightly bonded tha…
One of the major problems in material science has been the difficulty in modification of the most endurable material, diamond, due to its extreme hardness and chemical inertness. Here, we report the development of a conical structure of diamond by performing bias-assisted reactive ion etching in hydrogen plasma. The d…
A particle-based model for phonon transport and the scattering of phonon wave packets at interfaces is developed. The model, which incorporates the interference effects associated with the wave nature of phonons, is parametrized with frequency-dependent scattering rates obtained from molecular-dynamics simulations of…
The phonon spectrum of cubic Si3N4 was calculated by first-principles techniques. The results permit an assessment of important mechanical and thermo-dynamical properties such as the bulk modulus, lattice specific heat, vibration energy, thermal expansion coefficient, and thermal Grüneisen parameter for this compound.…
Antiferroelectric PbZrO3 films had been grown on LaNiO3/Pt/Ti/SiO2/Si wafers using a sol-gel process. The electric field-induced antiferroelectric (AFE) to ferroelectric (FE) phase switching behaviors was examined by the polarization versus electrical field measurements as a function of temperature and film thickness.…
Photoluminescence (PL) spectroscopy of individual silicon nanowires has been investigated. A narrow emission band (85 meV) was observed associated with a fast luminescence decay in the picosecond region and is considered due to the recombination relaxation of confined electronic states. The optical anisotropy was foun…
Abstract A series of biodegradable plastics from soy protein isolate (SPI) and lignosulfonate (LS) with a weight ratio of 0:10 to 6:4 were prepared with 40 wt % glycerol as a plasticizer by compression molding. Their properties were investigated by wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry…
Abstract The melt‐direct intercalation method was employed to prepare poly(propylene) (PP)–maleic anhydride grafted poly(propylene) (PP‐g‐MAH)–organic‐montmorillonite (Org‐MMT) nanocomposites. X‐ray diffractometry (XRD) was used to investigate the intercalation effect, crystallite size, and crystal cell parameter in t…
Transmission electron microscopy was used to probe the compositions of individual Co–Mo bimetal catalyst particles and the morphologies of carbon nanotubes (CNTs) catalyzed by these particles under flowing carbon monoxide at 700 °C. It was found that the composition of the catalyst particle at a CNT tip and the distri…
The magnetocaloric effect was investigated in LaFe11.7Si1.3, which undergoes a first-order transition at ∼188 K from the ferromagnetic to paramagnetic state. The magnetic entropy change upon a field increase from 0 to 5 T is as large as 29 J/kg K (212 mJ/cm3 K). The adiabatic temperature change obtained via direct mea…
Spider silks were implanted subcutaneously in pigs for a study of the tolerance against this material. Four types of spider silks of high purity and cleanliness were implanted: (i) major ampullate dragline silk reeled from the golden silk spider Nephila clavipes, (ii) native (unsterilised) silk reeled from a Brachypel…
Elastic constants of two-dimensional (2D) colloidal crystals are determined by measuring strain fluctuations induced by Brownian motion of particles. Paramagnetic colloids confined to an air-water interface of a pendant drop are crystallized under the action of a magnetic field, which is applied perpendicular to the 2…
Pulsed-plasma chemical vapor deposition of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane (V3D3) and water produced thin films with significant Si–OH content. Subsequent annealing of the films resulted in condensation of proximal Si–OH groups, further generating a Si–O–Si network and strengthening the film. Fourier-tr…
In the present work, we have reported the phase transition behavior of sol–gel-derived BaZr0.4Ti0.6O3 (BZT40) thin films. The dielectric properties of these films were measured as a function of temperature in the frequency range of 1 kHz to 1 MHz. A broad dielectric anomaly coupled with the shift of dielectric maxima…
Reaction mechanisms and activation energies for the complete conversion of ethene to ethene epoxide on two recently characterized oxidized Ag{111} surfaces have been determined from density functional theory. On both surfaces, epoxidation proceeds through a two-step nonconcerted mechanism via an oxametallacycle interm…