Materials Literature
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Epitaxial (001) diamond film were grown on mirror-polished single-crystalline (001) silicon substrates by microwave plasma chemical vapor deposition from a methane/hydrogen gas mixture. The films were characterized by means of scanning electron microscopy, Raman spectroscopy, and x-ray analysis. The results show that…
We have found that diamond can be synthesized from a mixture of CH4 and N2 without adding any H2. This new synthesis is sharply different from the common practice of diamond growth by chemical vapor deposition, which uses a hydrogen-rich mixture of CH4 and H2. In this new approach, nitrogen becomes an active component…
The crystal structure of a stable silyl cation, triethylsilylium, in the form of its tetrakis (pentafluorophenyl)borate salt [Et(3)Si(+) (C(6)F(5))(4)B(-)] (Et, ethyl) shows no coordination between cation and anion. The closest silicon-fluorine distance is greater than 4 angstroms. A toluene solvent molecule is close…
In dielectric multilayer optical coatings, laser induced damage is often associated with micrometers -scale surface defects such as the well known nodule defect. The interaction mechanism of the laser light with the coating defects is not understood, however. Historically, laser damage has been associated with peaks i…
Barium titanate thin films were deposited on metallic conducting BaPbO3 ceramic substrates by the sol-gel method using metal alkoxides. The thin films with a thickness of around 0.4 μm were confirmed to have a perovskite structure and to be highly resistive with a resistivity of more than 1011 Ω cm at room temperature…
The complex dielectric constant of ${\mathrm{Rb}}_{0.40}$(${\mathrm{ND}}_{4}$${)}_{0.60}$${\mathrm{D}}_{2}$${\mathrm{PO}}_{4}$ has been measured in the frequency interval from 1 mHz to 1 GHz at temperatures between 40 and 140 K. A novel frequency-temperature plot of the data is introduced to show that the behavior of…
Studies of icosahedral quasicrystals have revealed a conductivity pseudogap much narrower than the density-of-states pseudogap, resulting in a rapid suppression of electron diffusivity inside the latter. In contrast, measurements of the new metallic compounds ${\mathrm{Al}}_{2}$Ru show the formation of a semiconductin…
Discusses the three-stage numerical exposition of the effects of quenched disorder on phase ordering dynamics. The authors study the effects of random fields on domain growth. The numerical results indicate that the domain growth law is logarithmic for both the cases with non-conserve and conserved order parameter. Th…
A family of quasicrystals of dimensions 1, 2, 3, 4 governed by the root lattice E 8 is constructed. The use of the icosian ring, found in the quaternions with coefficients in Q( square root 5), allows simultaneous interpretation of the construction both in physical space and as a result of the standard 'cut-and-projec…
The conductivity \ensuremath{\sigma} of a series of AlCuFe and AlPdMn quasicrystals and approximant phases can be written \ensuremath{\sigma}(T)=${\mathrm{\ensuremath{\sigma}}}_{4}$ K+\ensuremath{\delta}\ensuremath{\sigma}(T). The ${\mathrm{\ensuremath{\sigma}}}_{4\mathrm{}\mathrm{K}}$ term is very low, decreases with…
The luminescence behavior of thermally oxidized porous silicon has been examined at various temperatures and times. No blue shifting of the photoluminescence has been noted with extended oxidation time (3–120 min), in a range where a 30% oxide thickness increase has been reported. This result does not easily fit the q…
The optical functions of several forms of thin-film silicon (amorphous Si, fine-grain polycrystalline Si, and large-grain polycrystalline Si) grown on oxidized Si have been determined using 2-channel spectroscopic polarization modulation ellipsometry from 240 to 840 nm (∼1.5–5.2 eV). It is shown that the standard tech…
The temperature dependence of the Vickers hardness is measured on the basal (0001) plane of single crystal α-Al2O3 (sapphire) from room temperature to 1273 K. The plastic zone surrounding the indents is investigated using selective chemical polishing and etching, optical microscopy, and transmission electron microscop…
A reference that offers comprehensive discussions on every important aspect of aluminum bonding for each level of manufacturing from mill finished to deoxidized, conversion coated, anodized, and painted surfaces and provides an extensive, up-to-date review of adhesion science, covering all significa
The electric field present in an inisotropic medium confined in a spherical cavity within an isotropic medium has been calculated. We considered a nematic liquid crystal with a cylindrically symmetrical director configuration with the symmetry axis along the direction of an applied a.c. electric field. The mesophase a…
With the help of a tunneling capacitance dilatometer we have measured the thermal expansion near the Peierls temperature (${\mathit{T}}_{\mathit{C}}$) in three charge-density-wave materials. For the layered compound 2H-${\mathrm{TaSe}}_{2}$, the expansion was measured along the basal plane, while in the trichalcogenid…
the increase of ferrite content. However, the nearly ferritic alloy showed much better passivation behavior, presumably due to the addition of 6% Cr.In aerated solution, no or very small passive region was observed. From the immersion test, the general corrosion was found to be minor. Pitting corrosion was the primary…
A decagonal phase which was grown from an icosahedral phase in a rapidly solidified Al 70 Pd 20 Mn 10 alloy by annealing at 800°C was examined by means of high-resolution electron microscopy. From the high-resolution image, we directly determined a two-dimensional arrangement of atom clusters, which are structural uni…
The electron effective mass of the conduction band in direct-band-gap ${\mathrm{GaAs}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{P}}_{\mathit{x}}$ alloys (x0.4) is reevaluated. A direct determination of ${\mathit{m}}^{\mathrm{*}}$ using the optically detected cyclotron resonance technique is presented for the low…
NaB(OH) 4 , M r =101.83, monoclinic, P2 1 /a, a=5.886 (3), b=10.566 6), c=6.146 (3) A, β=111.60 (4) o , V=355.4 (3) A 3 , Z=4, D x =1.903 Mg m -3 , λ(Mo Kα)=0.71069 A, μ=0.27 mm -1 , F(000)=208, room temperature, R=0.030 for 882 observed reflections with I>3σ(I). The structure consists of six-coordinate Na + in caviti…