Materials Literature
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The magnetic properties and field-dependent specific heat of melt-spun amorphous RE70TM30 (RE=Gd, Tb, Dy, Ho and Er; TM=Fe and Ni) and Gd65Co35 alloys were investigated as potential magnetic refrigerants. Essentially zero magnetic hysteresis was observed in all the Gd–TM alloys at temperatures from 5 K up to the order…
In the present bond-valence concept the bond-valence parameter r o is treated as constant for a given pair of atoms, and it is assumed that the bond valence s ij is a function of the corresponding bond length D ij , and that the atomic valence is an integer equal to the formal oxidation number for V i derived from sto…
Sodium sulfate, Na2SO4, has been reported to exist in five polymorphous forms labelled I–V. Structure analysis has been reported on three of the polymorphs and thermal analysis on all of them. The system has been reinvestigated by differential scanning calorimetry (DSC) and by X-ray powder diffraction at several tempe…
Lead titanate (PT) sols were prepared using propanediol, butanediol, or pentanediol solutions of lead acetate trihydrate and titanium diisopropoxide bis(acetylacetonate). Precursor sols for PbZr 0.53 Ti 0.47 O 3 (PZT) films were prepared from propanediol solutions, with zirconium tetrapropoxide being used as the zirco…
Mathematical and computational evidence that strongly suggests that optimal solutions exist to single-band, normal-incidence antireflection coating problems is presented. It is shown that efficient synthesis and refinement techniques can quickly and accurately find such solutions. Several visible and infrared antirefl…
We present an algorithm to simulate the packing of large samples of spheres chosen from a truncated log-normal distribution for either correlated or uncorrelated distributions. Use of a concept known as the porosity index provides a means to control the final porosity of a packed sample within a range that spans limit…
The crystal structures of four hydroxylapatite (HA) samples prepared from solutions in the presence of 10, 15, 25 and 30 Mg-atom-% have been investigated by X-ray powder pattern fitting. The total magnesium content of the solid samples, as determined by chemical analysis, was 4.9, 14.1, 20.4 and 30.6 Mg-atom-%, respec…
Magnesium hydroxide, Mg(OH) 2 : M r = 58.3, trigonal, P {\bar 3} m 1, a = 3.148 (1), c = 4.779 (2) Å, V = 41.015 Å 3 , D x = 2.36 g cm −3 at room temperature; a = 3.145 (1), c = 4.740 (2) Å, V = 40.602 Å 3 , D x = 2.39 g cm −3 at 70 K; Z = 1, λ = 0.8330 (5) Å, μ = 1.78 cm −1 , F (000) = 9.503 fm; final R = 2.42, wR =…
Trichothiodystrophy (TTD) is a rare autosomal recessive disorder characterized by brittle hair with reduced sulfur content, ichthyosis, peculiar face, and mental and growth retardation. Clinical photosensitivity is present in approximately 50% of TTD patients but is not associated with an elevated frequency of cancers…
The Hamaker constants of eight different ceramic materials, 6H‐SiC, tetragonal, partially stabilized ZrO 2 (3% Y 2 O 3 ), β‐Si 3 N 4 , α‐Al 2 O 3 , Y 2 O 3 , sapphire (single‐crystal α‐Al 2 O 3 ), MgO, MgAl 2 O 4 , and fused silica, across air, water, and n ‐dodecane at room temperature and across silica at 2000 K hav…
The deformation pattern at grain boundaries and at triple junctions in polycrystalline high purity aluminium (99.999%) has been studied by electron back scattering pattern (EBSP) observations. Specimens of two different grain sizes rolled to give 5% and 30% reductions have been examined by these different EBSP scans:…
The thermoelectric effect and its systematic variation with doping level ($x$), temperature ($T$), and external magnetic field ($H$) have been investigated for crystals of double-exchange ferromagnets, ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ ($0.15<~x<~0.50$). Large $T$- an…
High-performance polymers are used in applications demanding service at enhanced temperature while maintaining their structural integrity and an excellent combination of chemical, physical, and mechanical properties. Some of the important polymers in this respect are polyimides, polyamides, and polybenzazoles. However…
A Nd‐doped HfO 2 ‐Y 2 O 3 ceramic having excellent transmittance was synthesized by HIPing, using high‐purity powders (>99.99 wt%) of Y 2 O 3 , Nd 2 O 3 , and HfO 2 . The mixed powder compacts of these powders were sintered at 1650°C for 1 h under vacuum and HIPed at 1700°C for 3 h under 196 MPa of Ar. The specimen…
Localized {100} fiber textured diamond films were grown by addition of 20–200 ppm nitrogen into the gas phase during hot-filament chemical-vapor deposition (CVD). Cathodoluminescence indicates the presence of the nitrogen-vacancy system in the {100} textured diamond, whereas a blue ‘‘band A’’ luminescence is normally…
It is now well known that Si, B and OH+F are variable components of tourmaline, and yet the stereochemical details of their variation in the tourmaline structure are still not well characterized or understood. Application of the valence-sum rule of bond-valence theory to questions of short-range atomic arrangements sh…
Microstructure, cathodic polarization, and ohmic resistance on the cathode side of ‐based solid oxide fuel cells have been studied for the intermediate temperature operation range between 700 and 900°C. Starting powder characteristics, powder calcination temperature, and sintering temperature strongly influence the fi…
A ceramic‐matrix composite (CMC) that exhibits damage‐tolerant behavior without “weak” interfaces has been demonstrated. The concept relies on the heterogeneous distribution of fiber bundles within a porous matrix having homogeneous, fine porosity. It also depends on the development of residual stress from thermal exp…
The sonolytic degradation of aqueous carbon tetrachloride is investigated at a sound frequency of 20 kHz and 135 W (112.5 W cm - 2 ) of power. The observed first-order degradation rate constant in an Ar-saturated solution is 3.3 × 10 - 3 s - 1 when the initial CCl 4 concentration, [CCl 4 ] i, is 1.95 × 10 - 4 mol L -…
General Survey. Quantum Theory and Magnetism. Spin and Magnetization, Statics and Dynamics. Magnetostatics, Magnetic Domains and Magnetic Design. Survey of Magnetic Materials. Special Topics. Appendices. Indexes.