Materials Literature
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The transmission (ηT) and backscattering (ηR) of electrons with energies between 0.5 and 4 keV in thin films of Be, Al, Ge, Cu, and Ag, together with their secondary yields (δT, δR), were measured with a three-collector system. The SE efficiencies of backscattered electrons were 3 to 15 times greater than those of inc…
The intrinsic splay, twist, and bend deformations of nematic molecules are discussed. The intrinsic twist deformation leads to the cholesteric phase. On this molecular basis, the helical twisting power of cholesteric mixtures is discussed. The intrinsic splay and bend deformation cannot induce spontaneous deformation…
A recent proposal of Simmons and co-workers for the analysis of high-field thermally stimulated currents is extended to the case of thermoluminescence, with significant advantages for the study of continuous distributions of traps in bulk samples. The effect of the temperature smearing of the occupation function is al…
Rate coefficients have been determined in a drift tube-mass spectrometer apparatus for the oxidation reactions of Ti+ and Th+ ions in O2 and NO for ion mean energies ranging from thermal (300 K) to 5 eV. Formation of the first oxides of metal ions M+ in the reactions M+ + O2 (NO) → MO+ + O (N) is found to occur with r…
We have studied, both for the Kronig-Penney model and in general terms, the charge disturbance induced in a filled band of electrons by a solid surface. The existence of surface-charge quantization in a filled band is demonstrated and a division of energy bands into two types is made on this basis. The complementary r…
The LiD and LiH conductivities have been compared in the temperature range 300-900\ifmmode^\circ\else\textdegree\fi{}K. In both (LiD and LiH) the conductivity curve ${log}_{10}(\ensuremath{\sigma}T)=f(\frac{1}{T})$ shows three linear regions: (i) an intrinsic, (ii) a dissociation, and (iii) an association region. In a…
The valence-band structures of the light actinides thorium, uranium, and their dioxides have been investigated by means of x-ray photoemission spectroscopy. This study shows that the electronic structures of Th${\mathrm{O}}_{2}$ and U${\mathrm{O}}_{2}$ are quite similar, except for the presence of $5f$ electrons in U$…
The paraffin C33H68 undergoes three solid-solid phase transitions between room temperature and the melting point. The orthorhombic modification (A) stable at low temperatures is followed by two different monoclinic forms (B: 54.5°C < T < 65.5°C; C: 65.5°C < T < 68°C) and by the ``rotator ph…
We report a study of the infrared and Raman spectra of bulk glasses in the binary alloy system ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{S}}_{x}$ ($0.90\ensuremath{\ge}x\ensuremath{\le}0.55$). The spectra are interpreted in terms of models based on covalent bonding in which the $8\ensuremath{-}N$ rule is satisfied; i.…
We describe the relation between the observed behavior of photoemission energy distributions vs frequency, angle, etc., and the quantum theory of photoemission as recently set forth formally by Caroli et al. We derive a Fermi's Golden-Rule formula for the angle- and energy-resolved photocurrent from an independent ele…
High-resolution electron diffraction patterns have been obtained from frozen, hydrated catalase crystals to demonstrate the feasibility of using a frozen specimen hydration technique. The use of frozen specimens to maintain the hydration of complex biological structures has certain advantages over previously developed…
Abstract Poly‐[2,2′‐(m‐phenylene)‐5,5′‐bisbenzimidazole] (PBI) was originally developed as a fiber‐forming polymer for military applications. The eventually established intrinsic nonflammability (LOI 48%) and high moisture regain (13%) expanded application areas significantly; e.g., into protective suits. More recentl…
Photoemission spectra have been recorded for the dichalcogenides of several metals in groups IVA and IVB, using incident photon energies of 21.2, 40.8 and 48.4 eV. Considerable structure is resolved in the valence bands which are based mainly on chalcogen p orbitals. An interpretation given in terms of a simple LCAO m…
The calculation of radiative transition probabilities between two rare earth energy levels using the Judd-Ofelt approach is extended to include J mixing. The theory is used to explain a purely radiative transition in Eu 3+ when situated in two different host materials. Next the theory is applied to the 4 S 11/2 transi…
The influence of rare-earth (RE) impurities as well as the host ions in the thermoluminescence (TL) of CaSO 4 phosphors has been studied in detail by recording the TL glow curves, TL emission spectra and electron spin resonance (ESR) spectra of a number of gamma-irradiated CaSO 4 samples doped individually with differ…
Water vapor that condenses on a metal surface at 10 degrees K forms a noncrystalline phase of estimated density 1.2 grams per cubic centimeter. X-ray diffraction data of high precision and resolution have been analyzed to yield oxygen atom pair correlation functions. The positional correlation in amorphous solid water…
Abstract Die optische Absorption von 3d‐Übergangselementen in geschmolzenem SiO, wird untersucht.
A microscopic theory of ionic transport in superionic conductors is presented. Based on a liquidlike description of the ionic carriers, it describes the frequency and temperature dependences of the conductivity. A sum rule is obtained and the theory predicts the existence of a conductivity peak which scales with the i…
The influence of the eccentricity of electrostatic lenses on the spot size is analytically formulated and is numerically evaluated for the Butler type lens and the three anodes accelerating lens. For the aperture size which gives the minimum spot size, it is found that the misalignment less than 100 µm between the ano…
Electronic and nuclear inelastic scattering in surface channeling are studied in detail for slow ions. The transition probability of inelastic scattering is obtained as a function of the position (measured from the first atomic layer) and the scattering angle. As an example, we calculate 10- and 100-keV ${\mathrm{H}}^…