Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
We have studied growth condition dependence of magnetic and transport properties of magnetic semiconductor (GaMn)As grown by low-temperature molecular-beam epitaxy (LT-MBE). With increasing substrate temperature and decreasing As overpressure during the growth of (Ga1−xMnx)As with x=0.043, the hole concentration incre…
In this work, the compatibility of blends of plasticized poly(vinyl chloride) (p-PVC) and thermoplastic polyurethane (TPU) was investigated using a dynamic mechanical analyzer and scanning electron microscopy. Two kinds of TPU with different ratios of hard to soft segments, i.e., TPU90 and TPU70 were compared. p-PVC/T…
Several dialkyl and fluoro bis-tolane liquid crystals were synthesized and their physical properties evaluated. These highly conjugated liquid crystals exhibit a wide nematic range, small heat fusion enthalpy, high birefringence, and relatively low viscosity. Their excellent compatibility with commercial cyano mixture…
We show that for itinerant $3d$ transition metal systems the magnetocrystalline anisotropy energy is directly related to the anisotropic part of the spin-orbit interaction, rather than to the orbital part of the magnetic moment as was previously suggested. We further show how the spin-orbit anisotropy can be obtained…
We study vicinal crystal surfaces within the terrace-step-kink model on a discrete lattice. Including both a short-ranged attractive interaction and a long-ranged repulsive interaction arising from elastic forces, we discover a series of phases in which steps coalesce into bunches of $n_b$ steps each. The value of $n_…
Many studies have confirmed that cracks in brittle materials branch when the crack speed exceeds a certain threshold velocity, but the value of that threshold is not understood. Almost all theoretical calculations overestimate the threshold by factors of two or more. We show that thermal noise can reduce the threshold…
$\mathrm{NH}\ensuremath{\cdots}\mathrm{N}$ hydrogen bonded crystals of $[{\mathrm{C}}_{6}{\mathrm{H}}_{7}{\mathrm{N}}_{2}{]}^{+}\ifmmode \dot{}\else \.{}\fi{}{\mathrm{ClO}}_{4}^{\phantom{\rule{0ex}{0ex}}\ensuremath{-}}$ and $[{\mathrm{C}}_{6}{\mathrm{H}}_{7}{\mathrm{N}}_{2}{]}^{+}\ifmmode \dot{}\else \.{}\fi{}{\mathrm…
A series of titanium aluminophosphate molecular sieves with four different structure types including TAPO-5 (AFI topology), TAPO-11 (AEL topology), TAPO-31 (ATO topology), and TAPO-36 (ATS topology) have been studied to determine the titanium location in the aluminophosphate framework. Some Ti(IV) was reduced to param…
λ-(BETS) 2 GaBr x Cl 4 - x [BETS = bis(ethylenedithio)tetraselenafulvalene; 0 ≤ x ≤ 2] is a molecular superconductor with strongly correlated conduction electrons. The electrical transport properties of λ-(BETS) 2 GaBr x Cl 4 - x are drastically changed by varying the bromine content x or by applying pressure. At ambi…
The first study on the growth process of an array comprising colloidal semiconductor nanoparticles (quantum dots) is presented. Two types of particles, CdS and CdSe/CdS (core/shell), suspended in pyridine and water, respectively, have been used. A liquid drop containing the particles is placed on a solid substrate, an…
Polyphosphazene single-substituent polymers were synthesized with the general formula [NP(OCH 2 CH 2 OCH 2 CH 2 XCH 3 ) 2 ] where X = oxygen for polymer 5 or X = sulfur for polymer 6 . Characterization of these materials made use of 1 H, 13 C, 15 N, and 31 P nuclear magnetic resonance (NMR) spectroscopy, differential…
This paper describes the partial discharge (PD) characteristics and V-t characteristics of several insulating materials, such as liquid crystal polymer, epoxy resins, polyimide, and polyethylene-terephthalate (PET) with a needle-plane electrode system at elevated temperature. The life index n for an applied electric f…
The results of the structural determination of barium calcium tetragallium octaoxide, BaCaGa 4 O 8 , from X-ray (Cu Kα) powder diffraction data and refinement by the Rietveld technique are presented. In BaCaGa 4 O 8 , GaO 4 tetrahedra are arranged in a tridymite-like framework. The arrangement of GaO 4 tetrahedra has…
We determined the structure and electronic properties of cleavage steps on CdSe $(112\ifmmode\bar\else\textasciimacron\fi{}0)$ and $(101\ifmmode\bar\else\textasciimacron\fi{}0)$ surfaces from atomically resolved scanning tunneling microscopy images. Steps occur in high concentrations and are always oriented parallel t…
We have measured the longitudinal magnetoresistance ρ z z of graphite in high magnetic fields of up to ∼37 T at low temperatures down to ∼0.6 K. A dramatic increase in ρ z z was newly found in the high-field-low-temperature region. We have also found prominent non-ohmicity in the current-voltage characteristic in ρ z…
4-[(3,5-Di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxo-cyclohexa- 2,5-dienylidene)methyl]styrene (abbreviated as (p-vinylphenyl)hydrogalvinoxyl) was polymerized using AIBN as an initiator to give a bright yellow polymer with Mw = 3.2 × 104. The polymer was oxidized to give the corresponding polyradical derivat…
The self-diffusion coefficient and the shear viscosity are calculated for a system evolving under dissipative particle dynamics in two and three dimensions. The self-diffusion coefficient agrees with that Marsh et al. although the shear viscosity has corrections absent in previous theories. These corrections arise fro…
The title compound was synthesized by high-temperature solution reaction and its structure determined by X-ray diffraction techniques. The structure contains Ca 4 O 19 tetramers which form double chains extending along the a direction. The double chains are linked to form layers and B 2 O 5 groups bridge these adjacen…
We have measured the variation of the value of the thermal diffusivity of semi-insulating GaAs in the 100–305 K range. The method used is the pulsed photothermal displacement technique. This is a noncontact technique, and the value of the thermal diffusivity is derived from the temporal evolution of the signal rather…
The properties of transition-metal oxides are related to the presence of elements with mixed valences, such as Mn and Co. Spatial mapping of the valence-state distribution of transition-metal elements is a challenge to existing microscopy techniques. In this letter, using the valence-state information provided by the…