Materials Literature
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Conventionally, the theory of boundary scattering ignores the dependence of the reflection coefficient (p) on the electron wave vector. An alternative possibility, that the reflection coefficient changes abruptly from 1 to 0 when the change of wave vector on specular reflection exceeds a certain value, is explored her…
The crystal structure of Ga2—xFexO3, with 0.7≤x≤1.4, has been determined at 298°K by x-ray diffraction. Ga2—xFexO3 crystallizes in the orthorhombic system, space group Pc21n, with lattice constants a = 8.7512±0.0008, b = 9.3993±0.0003, c = 5.0806±0.0002 Å and eight formula weights in the unit cell. The complete scatte…
Abstract The effect of cooling, nucleation, and spherulitic growth rates on the properties of polypropylene is discussed briefly. A differential thermal analysis technique is described for evaluating the relative extent of heterogeneous nucleation that occurs in a particular polypropylene composition. The method is ba…
Measurements have been made of the fraction of an electron beam backscattered from thin films of copper and gold at incident energies from 5 to 25 kev. The results from very thin films indicate that approximately 50% of backscattering from a solid target must be due to single scattering. A comparison with existing the…
The electrical conductivity of M 2 O 3 ‐ZrO 2 compositions containing 6 to 24 mole % M 2 O 3 , where M represents La, Sm, Y, Yb, or Sc, was examined. Only Sm 2 O 3 , Y 2 O 3 , and Yb 2 O 3 formed cubic solid solutions with ZrO 2 over most of this substitutional range. Scandia forms a wide cubic solid solution region w…
Abstract A study has been made of the effect of increased time of mixing carbon black in rubber on the dynamic properties of the carbon black‐rubber vulcanizates. Increased time of mixing reduces the dynamic modulus and dynamic viscosity as well as the phase angle at moderate amplitudes of oscillation. The changes in…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Measurement of Surface Tension by the Pendant Drop TechniqueClyde E. StaufferCite this: J. Phys. Chem. 1965, 69, 6, 1933–1938Publication Date (Print):June 1, 1965Publication History Published online1 May 2002Published inissue 1 June 1965https://pubs.acs.org/doi/10.1021/j…
Dielectric constant κ′, loss κ″, and conductivity σ of single crystals of CoO, NiO, and mixed crystals of CoO–NiO as a function of frequency from 102 to 1010 cps and temperature from −193°C to 400°C have been determined. The dielectric constant κ′ is constant (12.9 at 25°C) in the whole frequency range in CoO. It decr…
We have correlated the experimentally measured intensities of the solution absorption spectra of Pr3+, Nd3+, Er3+, Tm3+, and Yb3+ in three different solvents with a theoretical expression derived by Judd. The expression, P=Σ lim λTλσ(fNψJ‖∪(λ)‖fNψJ′′)2λ=2,4,6is derived from a theory in which the ligand-field interacti…
The temperature dependence of the complex dielectric constants at 9.2 Gc/sec are reported for a series of partially deuterated potassium dihydrogen phosphate crystals as well as for a potassium dihydrogen arsenate and an ammonium dihydrogen phosphate crystal. The transition temperature, the high-temperature loss tange…
The assignment of the normal-mode spectrum in perovskites has been achieved by a comparison of the vibrations of calcium, strontium, barium, and lead titanates and zirconates. In addition, for the antiferro-electric material lead zirconate, about 90% of the value of the low-frequency dielectric constant is the result…
The effects of data termination and systematic errors on the radial distribution functions of liquids obtained from x-ray diffraction data are investigated with the aid of a computer. A general procedure for the elimination of spurious detail is presented, and new data for liquid mercury and lead are analyzed. Compari…
It is shown that the existence of an orbital degeneracy in the $3d$ band may lead to a change of sign of the magnetostriction, when this degeneracy goes through the Fermi level. Such a change of sign is observed in the Fe-Ni and Co-Ni alloy series (permalloy), at an electron concentration of 27.7 electrons per atom. A…
Piezoelectric paramagnetic crystals can show a linear dependence of the paramagnetic susceptibility on an applied electric field. This effect has been detected in NiS${\mathrm{O}}_{4}$\ifmmode\cdot\else\textperiodcentered\fi{}6${\mathrm{H}}_{2}$O at low temperatures. The thermodynamic inverse effect, the creation of a…
The electrical resistivity $\ensuremath{\rho}$, the Seebeck coefficient $Q$, and the thermal conductivity $\ensuremath{\kappa}$, were measured in a series of GaAs samples in the temperature range 300-900\ifmmode^\circ\else\textdegree\fi{}K. Values of $Q$ were combined with room-temperature values of the Hall coefficie…
The Madelung constants for the 4–4, 3–5, 2–6, and 1–7 tetragonal perovskite structures have been calculated for axial ratios α=c/a varying from 0.90 to 1.10. Least-squares fits expressing the Madelung constant as a function of (1—α) are reported.
The 11B1H molecule of Σ+ symmetry is predicted, on the basis of perturbed Hartree—Fock calculations in which the origin is chosen at the B nucleus, to have a magnetic susceptibility of 18.16 ppm (paramagnetic!), a rotational magnetic moment of −8.17 μN, shielding constants at B of −264 ppm and at H of 22.6 ppm, and sp…
Electron paramagnetic resonance studies of the tetrahedral CuCl4= ion in single crystals of Cs2CuCl4 and Cs2ZnCl4 yield the spectroscopic parameters g1=2.083±0.001, g2=2.103±0.003, g3=2.384±0.006 (Cs2CuCl4) or 2.446±0.002 (Cs2ZnCl4), and | A1 | = (5.1±0.5)×10−3 cm−1, | A2 | = (4.6±0.5)×10−3 cm−1, and | A3 | = (2.5±0.5…
From simple considerations of the different ways in which ammonia may be introduced into the structures of metal ammine salts it is evident that while the ammonia molecules tend to be coordinated to the metal ions they otherwise behave as rather inactive groups towards their remaining environment. Accordingly a factor…
The metastable form of acetamide has been studied by X-ray diffraction. The crystals are orthorhombic, space group Pccn, a=7"76, b= 19.00, c= 9"51/~, Z= 16. There are two molecules in the asymmetric unit. These are bound in two-molecule units by a pair of hydrogen bonds. Further hydrogen bonds link these dimers togeth…