Materials Literature
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The current state of polaron theory as applicable to transition metal oxides is reviewed, including problems such as impurity conduction where disorder plays a role. An estimate is given of the conditions under which polaron formation leads to an enhancement of the mass but no hopping energy. The binding energy of a p…
Abstract Polymere mit phthalocyaninrtiger Struktur ergaben sich durch Reaktion von einigen schwefelhaltigen Komplexen, die vier Nitrilgruppen enthalten, mit Kupferacetylacetonat bei höherer Temperature. Die Leitfähigkeiten der Polymeren liegen zwischem 6,3·10 −3 und 2,1·10 −10 Ohm −1 cm −1 . Die Aktivierungsenergie ze…
Ninety-one samples of diatomaceous rocks collected from seven separate sections of the Miocene and Pliocene strata of Oga Peninsula. Akita Prefecture, were studied. The samples are from, in ascending order, the upper part of the Onnagawa Formation, the Funakawa Formation, the Kitaura Formation, the Wakimoto Formation…
Abstract The synthesis of N‐vinyluracil, N‐vinylthymine, and N‐vinyladenine is described. The general procedure consists of the conversion of the corresponding nucleric acid bases to their N‐hydroxyethyl compounds, followed by chlorination to the N‐chloroethyl compounds and dehydrochlorination to the N‐vinyl derivatie…
Examination of the organic matter in some modern and fossil oolites has shown that it contains protein, with a high content of acidic amino acids. Artificial oolites from a water-processing plant contained no amino acids. The protein matrix may influence the formation of natural oolites by concentrating calcium ions.
Resistivity and Hall-effect measurements in ${\mathrm{Eu}}_{0.95}$${\mathrm{Gd}}_{0.05}$S give evidence for the onset of a well defined conduction band with critical scattering coexisting with magnetic impurity states.
Summary The microstructure of London Clay from several localities and depths was examined in thin section under the polarizing microscope. Except where severely weathered the clay was found to have a strong preferred particle orientation and frequent microscopic discontinuities. These features are compared with those…
Oxidation of octahedral ferrous to ferric iron in soil vermiculite clays and biotites increases the potassium-fixation capacity of vermiculites and increases the difficulty of replacing interlayer potassium in biotites. This unexpected effect is believed to be related to an increase in the attractive forces between po…
The magnon density of states of ferromagnetic Gd${\mathrm{Cl}}_{3}$ in an external magnetic field has been observed by means of high-resolution optical spectroscopy. The relevant transitions arise from a single-ion transition mechanism, but the initial (magnon) and in some cases the final (exciton) states of the trans…
Single crystals of BaS have been grown and irradiated with neutrons, producing an intense $F$-center spectrum with a spectroscopic splitting factor, $g=1.9637\ifmmode\pm\else\textpm\fi{}0.0005$. The isotropic part of the hyperfine interaction $A$ is 41.0\ifmmode\pm\else\textpm\fi{}0.2 and 36.4\ifmmode\pm\else\textpm\f…
We have computed the renormalization of the conduction-electron energy in a degenerate ferromagnetic semiconductor at zero temperature due to the virtual emission and reabsorption of spin waves. We find that as a result of the difference between the up- and down-spin Fermi momenta, this renormalization is quite small.…
The lattice parameters and the quadrupole splittings of the room-temperature Mössbauer spectra of the cubic A 2 FeSbO 7 pyrochlores (A = Sm, Eu, Gd, Tb, Y, Er, Lu) have been found to vary linearly with the Templeton–Dauben radii of the A 3+ ions. The variation of the quadrupole splitting can be correlated with the pos…
The polarization characteristics of the blue-copper luminescence in a cubic ZnS:Cu, I (Cl, Al or Ga) single crystal grown from the melt were investigated. The polarization with particular azimuthal dependences is observed under polarized characteristic excitation, indicating that the center has its own symmetry lower…
The recovery of neutron-irradiation-induced defects in tungsten has been investigated via isochronal resistivity studies after irradiations from 8.5\ifmmode\times\else\texttimes\fi{}${10}^{17}$ to 1.5\ifmmode\times\else\texttimes\fi{}${10}^{21}$ $n$ ${\mathrm{cm}}^{\ensuremath{-}2}$ (${E}_{n}>1$ MeV). These studies…
An optical transition at 1.986 eV in ZnTe has earlier been attributed to the radiative recombination of an electron-hole pair bound at an oxygen atom substituting isoelectronically for Te. In this paper the results of isotopic substitution and Zeeman experiments are offered to prove the correctness of this identificat…
The infrared spectra of acetonitrile and acetonitrile-d3 have been studied at − 50°C for the high-temperature (β) crystalline phase and at − 65°, − 115° and − 192°C for the low-temperature (α) crystalline phase. A powder x-ray pattern obtained at liquid-nitrogen temperature indicates that the unit cell is primitive or…
Magnetic perovskites BiMnO 3 and BiCrO 3 were synthesized under very high pressures. There are phase transitions at 500°K and 410°K at atmospheric pressure for BiMnO 3 and BiCrO 3 respectively, and the crystal distortion of each phase was determined. BiMnO 3 is ferromagnetic below 103°K, while BiCrO 3 is inferred to b…
The thermoreflectance spectra of Si, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgSe, and HgTe are reported. Measurements were made on most materials at both room and liquid-nitrogen temperatures. The positions of the peaks observed are compared with previous reflectance and electro…
Abstract Die Porphin‐Synthese aus in α‐Stellung unsubstituierten Pyrrolen und Aldehyden (Weg II im Schema S. 184) wird verbessert. ms ‐Tetraphenylporphin (4) und eine größere Anzahl weiterer ms ‐substituierter Porphine (Tab. 1) sind so auf einfache Weise rein und in guter Ausbeute zugänglich. Auch der raumerfüllende A…
Electron-spin-resonance spectra of N, P, As, and H atoms trapped in matrices formed from rare-gas elements at 4.2\ifmmode^\circ\else\textdegree\fi{}K have been studied. The isotropic hyperfine coupling of N and P increases with the atomic number of the matrix element whereas that of As decreases. The van der Waals int…