Materials Literature
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The operative slip systems, and the strain hardening behaviour in tension of single crystals of β′-AgMg (CsCl structure) has been investigated in the temperature range from 25 to 298 °K; a few compressive experiments are also reported. It is shown that β′-AgMg crystals deform by slip on the {112} 〈111〉, {110} 〈111〉, {…
The magnetic structures of antiferromagnetic manganese pyrophosphate and copper pyrophosphate have been determined by single crystal neutron diffraction techniques. There have been two previous determinations of the structure of manganese pyrophosphate. The discrepancy between these results is explained by postulating…
The low-temperature size effects in the phonon-drag thermopower and electrical and thermal conductivities of bismuth, measured under identical experimental conditions on a tuningfork sample of arm thicknesses 2.8 and 1.2 mm, are reported. The thin arm has the highest positive thermopower and a plateau is observed for…
Crystals of calcium fluorophosphate ${\mathrm{Ca}}_{10}$${(\mathrm{P}{\mathrm{O}}_{4})}_{6}$${\mathrm{F}}_{2}$ have been grown from melts of various compositions. Optical and ESR measurements have been performed on samples before and after various treatments such as a uv irradiation and a thermal quench. Two kinds of…
Longitudinal and transverse relaxation times of 119Sn have been measured as a function of temperature in liquid SnCl4 and SnI4. For SnCl4, T1 is a monotonically decreasing function of temperature and is dominated mechanistically by spin-rotation over the entire liquid range. In SnI4, T1 passes through a maximum near 1…
A new form of Cu 3 V 2 O 8 was prepared at 30 kbar and 900 °C. The unit cell has dimensions a = 6.2493(9), b = 7.9936(9), c = 6.3776(10) Å, β = 111.49(1)°, and the space group is P2/c. The crystal structure, refined by least-squares to a final R = 0.054, using 848 reflections, is similar to that of Mg 3 V 2 O 8 . Chai…
free path 1(k) will be parallel to k, and hence one may write 1 =7~V, OH 'e(rd ~/m )/(~d&')
In a molecular beam apparatus, a thermal beam of aluminum atoms (≈ 1700°K) intersects an uncollimated thermal beam of ozone molecules (300°K) and the resulting visible chemiluminescence is recorded with a 1 m scanning monochromator. The chemiluminescence spectrum consists of (1) the AlO B 2Σ+−X 2Σ+ blue-green system f…
Raman scattering and exciton luminescence and absorption have been studied in high-purity single-crystal ${\mathrm{Cu}}_{2}$O at liquid-helium temperature using 4880-\AA{} laser excitation. The Raman-active mode has been unambiguously identified at 515 ${\mathrm{cm}}^{\ensuremath{-}1}$, and the first observation made…
Surface modes play an important role in a solid's response to external disturbances. A charged particle on approaching or leaving the surface may suffer inelastic scattering owing to its coupling with these modes. The scattering rate is calculated in the Born approximation for two instances: (i) in metals, where the s…
The linear-combination-of-atomic-orbitals (LCAO) model of the preceding paper for the cubic-SrTi${\mathrm{O}}_{3}$ band structure is applied to predict the effect of the 110 \ifmmode^\circ\else\textdegree\fi{}K phase transition on the SrTi${\mathrm{O}}_{3}$ conduction bands. In this cubic-to-tetragonal structural tran…
The temperature and frequency dependence of conductivity, dielectric properties, infrared absorption, and electron-paramagnetic-resonance data are presented for semiconducting phosphate glasses based on oxides of Ti, V, Mn, Fe, Co, Ni, Cu, Mo, and W. The vanadate system is examined in a range of compositions, most of…
The nonrelativistic augmented-plane-wave (APW) method has been applied to calculate the electronic band structures for several cubic perovskite-type compounds, including KNi${\mathrm{F}}_{3}$, SrTi${\mathrm{O}}_{3}$, KMo${\mathrm{O}}_{3}$, and KTa${\mathrm{O}}_{3}$. These calculations involve ad hoc crystal potentials…
A theory is outlined of the aligning action of sound on nematic liquid crystals. It is based on sound-induced stresses and forces and identifies four contributions to the transverse stress. Formulas for the threshold sound intensities of a few simple deformations are given.
Experiments to reveal the influence of water concentration in obsidian upon the annealing rate of fission tracks showed that a 2.2% H2O obsidian would lose 70% of its tracks in 1 m.y. if held at 30°C. Data obtained at three temperatures (227°, 253°, and 282°C) give the possibility of extrapolations to geologically sig…
The step cascade with side flow is defined as a step cascade where uranium of lower assays than that from the final stage is withdrawn, and where also, in addition to the major feed, reprocessed spent uranium is introduced as minor feed. A method of calculation is proposed for finding the exact total flow rate of the…
Abstract The cation exchange capacity (C.E.C.) of nontronite was determined by titrating the acid clay, prepared by the action of H-resin on nontronite, in water and some nonaqueous solvents. The base-titratable acidities of the acid nontronite, freshly prepared as well as aged, were found to be greater than the acidi…
New vapor pressure data for cobalt have been obtained in the temperature range 1519–1926°K from Knudsen effusion experiments. The derived third-law heat of vaporization of cobalt is Δ H298°=101.0± 0.6 kcal/mole. Plausible explanations are presented that account for the widely differing vapor pressure data and heats of…
In the AE-bearing lead deposit of Korsns, apatite is the most common REmineral, monazite is a widespread accessory and allanite is a rare constituent. The paper describes one type of each. Also, the physical properties and chemical composition of the minerals are presented. The chemical analyses contain determinations…
The stress-optic coefficient ( n 3 /2)( q 11 - q 12 ) has been determined for a series of 18 optical glasses of different compositions in the wavelength range 5700-3200 Å. The coefficients are negative for all the glasses except for a high-lead-content glass of density 6·7 and refractive index 1·89. The numerical valu…