Materials Literature
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The optical absorption is studied as a function of γ-irradiation dose and composition for a series of magnesium phosphate glasses. The optical absorption spectra were measured in the wavelength range from 200 to 1100 nm at different γ-doses in the range from 0.2 to 1.0 Mard. The obtained results are analysed assuming…
Electromigration reliability of TiN barrier layer itself has been studied. Our results show no electrically measurable electromigration. Resistance increase and open failure under high density current stress are apparently due to a purely thermally activated process with an activation energy of 1.5 eV. TiN resistance…
A new perturbation method for the diffraction of a plane wave by a grating with periodic imperfections is presented. The originality of the method lies in the fact that the perturbation occurs on a reference profile that is not a plane but a grating. First, the diffraction by a reference grating is treated. At this st…
Luminescence properties of anodically produced porous silicon (PS) have been improved significantly by depositing In metal into micropores. Thin ( ∼300 nm) PS specimens were electrochemically plated in an indium sulfate solution. Observed room-temperature photoluminescence (PL) is very strong in intensity and narrow i…
X-ray diffraction provides an optimum resolution of about 10−4 Å−1 in reciprocal space. Using synchrotron radiation, very weak diffraction phenomena can be studied with this resolution. Careful examination of the prominent Bragg reflections of a decaprismatic Al70Co15Ni15 needle reveals contributions both from a perfe…
Abstract Complete ionic conductivity spectra as well as quasielastic and inelastic neutron scattering spectra have been taken of solid silver bromide at various temperatures. High-amplitude vibrational movements, essentially of the silver ions, contribute to both kinds of spectra. In particular, a conductivity maximu…
Abstract Hydrolysis of poly(ester urethane ureas) (PURUs) is a complex phenomenon which impedes the analysis of the relationships between their composition and hydrolytic stability. Hydrolytic stability of PURUs decreases due to rising (i) polyol acidity, (ii) content of ester groups, (iii) flexibility and (iv) hydrop…
The extent of substitution of Fe by Al in goethite in 32 lake ore samples collected from 11 lakes in Finland varied between 0 and 23 mol-%. The data indicated a negative relationship between Al-substitution and the particle size of lake ore. Differences in the Al-substitution were apparent between sampling sites, sugg…
This paper reports on the development of shape memory alloy based microactuators that can be integrated in teleoperated microsystems for medical applications. The use of shape memory alloys as actuator will increase the performance of micromechanical devices by several orders of magnitude. The paper presents the resul…
We determine the anchoring strength (W) for a lyotropic liquid crystal in the nematic calamitic phase. The sample holder is a microslide 200 \ensuremath{\mu}m thick (Vitro Dynamics) whose inner surfaces present some grooves introducing an easy axis. The technique used is based on the determination of the critical magn…
A statistical-mechanical theory which takes into account translational-translational, orientational-orientational, and mixed correlations, based upon the method of conditional distribution functions, is applied to calculations of the order parameters and surface free energy of a system composed of interacting ellipsoi…
Two charge states are observed for Ru in doped PbTiO3 crystals using electron paramagnetic resonance (EPR). The two paramagnetic charge states are +3 and +5. The g tensors for the Ru3+ and Ru5+ defects were found to be near axial: g∥≂1.155 and g⊥≂2.188 for the Ru3+ center and ge∥≂2.0045 and ge⊥≂3.959 for the Ru5+ cent…
Calculations of powder diffraction peaks using a model of tiny (diameter a few nm) spherical crystals log normally distributed in size with and without surface relaxation are presented. The calculated peak shapes are more nearly Gaussian than Cauchy (Lorentzian). Surface relaxation can produce small variations in peak…
The inorganic misfit-layer compound (SbS)(1.15)TiS2 was prepared by high-temperature reaction of the elements. The structure, determined by single-crystal X-ray diffraction, is described by two interpenetrating incommensurately modulated subsystems. The first subsystem comprises TiS2 sandwiches, with Ti atoms in trigo…
Measurements of the effective diffusion coefficient, De, of 222Rn in concrete are important for accurate determination of transport mechanisms and computer modeling of radon entry into structures. A method for in-situ determination of De as well as the emanation fraction, F, is described. It is based on continuous mea…
Thermally stimulated discharge currents and time domain dielectric spectroscopy were employed to characterize the behavior of clay-filled ethylene propylene rubber. Measurements were made on samples with different clay concentrations and particle sizes. The main effect of the clay filler on the electrical properties i…
A simple, unified form of the fluorine-fluorine interionic potential is deduced from the modelization of many fluoroperovskites through a rigid-ion model. The Born-Mayer potential appears to be the most convenient description (${\mathit{V}}_{\mathrm{F}\mathrm{\ensuremath{-}}\mathrm{F}}$=\ensuremath{\lambda}${\mathit{e…
Abstract Crystals of Na 2 [Bi 2 Cu 3 O 4 (AsO 4 ) 2 ] · H 2 O and K 2 [Bi 2 Cu 3 O 4 (AsO 4 ) 2 ] · 2 H 2 O were synthesized under hydrothermal conditions at T ≤ 503 K. Their crystal structures were determined from single crystal X-ray data (Na 2 [Bi 2 Cu 3 O 4 (AsO 4 ) 2 ] · H 2 O: a = 9.716(1) Å, b = 5,203(1) Å, c =…
Abstract The Middle Proterozoic (1.1 Ga) Nonesuch Formation, host of the stratiform copper deposit at White Pine, Michigan, consists of 200 m of principally dark grey clastic sediments which contain detritus obtained dominantly from underlying mafic to intermediate volcanic rocks. Clay minerals from samples collected…
In situ real-time scanning tunneling microscopy is used to study Si etching in alkaline solutions modified by addition of Triton, a commonly used nonionic surfactant. On Si(111), time sequences of images, with the resolution of atomic steps, show that the rate of the nucleation of etch pits is decreased on terraces wh…