Ternary Samples Research Articles

Derivative spectrophotometry in the determination of phenyl-beta-naphthylamine used as an antioxidant in rubber mixtures.

A method for the determination of phenyl-beta-naphthylamine (PBN) in ternary mixtures by second-derivative spectrophotometry is described. The procedure works without any separation step of PBN from the other polymer additives. By applying the second-derivative spectrophotometry, Beer's law was valid over the range 0.25-10 micro g mL(-1). The proposed method has been applied to the determination PBN in synthetic ternary mixtures and rubber samples. A comparative study of the results obtained using the second and the third-derivative spectrophotometric methods is presented and evaluated. The derivative spectrophotometric method indicated that the amount of PBN found after extraction from the rubber samples was 0.97+/-0.02 g/100 g of sample.

The Ternary System Li2O–Al2O3–B2O3: Compounds and Phase Relations

The ternary system Li2O–Al2O3–B2O3 is reinvestigated with solid-state reaction and X-ray powder diffraction technique to clarify some long-standing uncertainties. The phase relations are constructed based on the phase identifications of 51 ternary samples. Six ternary compounds, Li2AlB5O10, LiAlB2O5, Li3AlB2O6, Li2AlBO4, LiAl7B4O17 and a compound with a composition close to 0.66Li2O·0.06Al2O3·0.28B2O3, are observed or confirmed in this system, and the thermal stability of these ternary compounds is also discussed on the basis of DTA experimental results.

Reduction of Multiexponential Background in Fluorescence with Phase-Sensitive Detection

Fluorescence detection in a complex matrix often requires the reduction of background signals. Fluorescence lifetime-based methods have been an effective approach to suppressing the undesired background, especially when substantial spectral overlap precludes optical filtering. We introduce a methodology of suppressing a fluorescence background that contains multiple species for the quantification of a single fluorescent analyte. The method is based on the recognition that the multiexponential decay of the fluorescence background can be described by a single phase angle when the sample is excited by a sinusoidally modulated beam. The reduction of the total background is accomplished by setting the detector 90 degrees out of phase from the total background fluorescence. The background reduction is demonstrated with ternary samples containing pyrene (τ = 18.2 ns), anthracene (τ = 4.5 ns), and 1,4-bis(5-phenyl-2-oxazolyl)benzene (POPOP, τ = 1.35 ns). The component with the shortest lifetime (POPOP) is successfully analyzed after the background from longer-lived components (pyrene and anthracene) is reduced. The phase-sensitive detection enables simultaneous suppression of background fluorescence with lifetimes longer and shorter than the analyte, as demonstrated by the quantification of anthracene in a background composed of pyrene and POPOP. These samples present situations that cannot be treated by traditional methods of fluorescence background reduction. An effective fluorescence spectrum of the analyte is collected after the multiexponential background is eliminated. The method is especially useful when the total concentration of the background displays significant fluctuations. When the variations in the background fluorescence intensity are comparable or exceed the analyte fluorescence, the analyte cannot be quantified with steady state fluorescence measurements. The phase-sensitive method, however, effectively quantifies the analyte with excellent linearity in calibration.

Ageing phenomena and determination of the optical self absorption coefficient in PN junction

We have developed a model for the calculation of the induced current due to an electron beam with an extended generation profile. The analytical expression of the electron beam induced current (EBIC) is obtained by solving the steady-state continuity equation using the Green function method. In the case of a sulphur doped (Ga 0.7 Al 0.3 As:N + /Ga 0.7 Al 0.3 As:P) sample prepared by metalorganic vapour phase epitaxy (MOVPE) method, the experimental current profile, measured by SEM enabled us to calculate the diffusion length of the minority carriers ( L p = 1 μ m in the N region and L n = 1.80 μ m in the P region of the ternary sample). Far from the depletion layer, the experimental current profile measured provided us the optical self absorption coefficient of this sample: a p = 1.483 μ m −1 in the N region and a n = 0.167 μ m −1 in the P region. According to our EBIC model, the width of the depletion layer of this sample is about 0.8 μ m, while at elaboration of the sample, 10 years ago, the width of the depletion layer deduced from the characteristic curve I(V) was about 300−400 A. This widening of the depletion layer is due to the ageing of the diode.

Characterization and reactivity of V2O5-WO3 supported on TiO2-SO42− catalyst for the SCR reaction

V2O5 and WO3 supported on TiO2-SO42− have been characterized by BET, XRD, XPS, TPD and H2-TPR measurements. The comparison of the reactivity on SCR reaction of the catalysts with the support allows to understand the interaction of sulfate species with V2O5 and WO3. The sulfate deposited on TiO2 does not affect on its physical properties such as surface area and phase transformation. In TPD and H2-TPR, it is found that the sulfate stability strongly depends on the loaded metal oxides and the reduction property of V2O5 in ternary sample is changed due to the synergetic effect between V2O5 and WO3. The SCR reactivity of V2O5/TiO2-SO42− at low temperature becomes the same as that of V2O5-WO3/TiO2-SO42−, while at high temperature, the high NO conversion of V2O5-WO3/TiO2-SO42− is extended up to 450°C. Accordingly, it can be suggested that the strong interactions among the supported components on TiO2 play important roles in the modification of the SCR reactivity over TiO2-based catalyst.

The Deviation from Matthiessen's Rule at 4.2 K in Dilute Copper-Gold-Germanium Alloys

The deviation from Matthiessen's rule (DMR) of dilute copper-gold-germanium alloys was measured at 4.2, 77 and 273 K. The low-field Hall coefficient of binary Cu-Au and Cu-Ge alloys was also measured at 4.2 K to determine anisotropy parameters for the explanation of the DMR in the ternary alloys. In order to control the shape factor of the ternary samples the germanium content was brought into binary Cu-Au samples by vapour deposition and diffusion annealing. The limitation of the usual two-group model for the investigated alloys is shown and a more accurate three-group model is presented. Especially the DMR at 4.2 K of the ternary samples in the range 20-30 nΩ cm (as well as the DMR at 273 K) can be substantiated by the low-field Hall coefficient and by the anisotropy of scattering rates obtained from the de Haas-van Alphen effect for the binary alloys.

The ternary Gd-Li-Mg system: Phase diagram study and computational evaluation

The binary Gd-Li and the ternary Gd-Li-Mg systems were studied experimentally by thermal analysis and phase equilibration and also by thermodynamic calculations using the CALPHAD method. Ternary phase equilibria at 250 °C were studied with 55 different alloys that were annealed for 400 h and analyzed by x-ray diffractometry. A thermodynamic assessment of the binary Gd-Li system was also performed and the calculated phase diagram is presented. In the Gd-Li-Mg system, ternary solubilities of Li in GdMg (up to 5 at.% Li), GdMg2 (up to approximately 3 at.% Li), and GdMg3 (up to 5 at.% Li) were found at 250 °C. No ternary compound was observed. Lattice parameters for different compositions are given for these phases. Thermal analysis using a ternary key sample of composition near the invariant reaction L′=L+(βGd)+GdMg provided the data that were needed to determine a thermodynamic parameter for the ternary liquid. Thermodynamic data sets for the ternary solid solution phases were also developed. Based on the present data sets and those of the binary Gd-Mg and Li-Mg systems from the literature, the phase equilibria in the entire ternary system were calculated. Isothermal and vertical sections of the phase diagram and the projection of the liquidus surface are shown. These calculated phase diagrams are well supported by the experimental data.

Quantitative approach in x-ray shadow microscopy

A novel implementation of x-ray shadow microscopy or x-rayabsorption microscopy for analytical purposes has been developed. When using amicrofocus x-ray source (with an energy lower than 30 keV) for x-ray shadowmicroscopy, i.e. microradiography or microtomography, the measuredintensities are directly related to the spectral feature of the incident x-raybeam. In this paper, we describe in a theoretical way the problem ofquantitation without the use of any x-ray spectrometer, and we present anexperimental application on standard specimens (binary and ternary sample). Weshow that only the spectral distribution of the x-ray source used and thespectral response of the imaging sensor are needed to solve the question ofquantification. The accuracy of the method, and, more particularly, thepotential improvements of the current method are discussed at length. Academicusers may obtain the relevant calculation software, called SimulX, asfreeware, directly from the authors.

Hydrogenation characteristics of ternary alloys containing Ti 4Ni 2X (X=O, N, C)

Ti 2Ni-based alloys containing oxygen, nitrogen and carbon were investigated regarding their metallographic structures and hydrogenation characteristics. The alloy samples containing these non-metal elements had multi-phase structures composed of Ti 4Ni 2X, TiNi and TiX (X=O, N, C) phases. The ternary alloy samples reversibly absorbed and desorbed hydrogen under moderate conditions such as room temperature and atmospheric pressure. The hydrogenation properties of the alloy samples containing the non-metal elements were compared with those of the binary Ti 2Ni compound.

BiO 1.5–BO 1.5–GeO 2 glass system and crystallization of Bi 4Ge 3O 12 phase

The BiO 1.5–BO 1.5–GeO 2 ternary glass samples were prepared by fusion in a platinum crucible and cast in a brass mould. For each nominal composition a sample’s physical properties, such as glass transition ( T g), crystallization ( T x) temperatures and densities, were measured. The 45BiO 1.5–40BO 1.5–15GeO 2 (mol%) glass sample with T g=385±2°C, T x=517±2°C presented a density of 6.94±0.02 g cm −3. A non-isothermal crystallization study of this glass by differential scanning calorimetry (DSC) showed that the directionality of crystal growth was equal to 1.1 and that the activation energy was approximately 54 kcal mol −1. The presence of two crystalline phases, Bi 6B 10O 24 (surface) and Bi 4Ge 3O 12 (BGO) (bulk), were detected by powder X-ray diffraction (XRD) and composition analysis. Experiments of isothermal crystallization showed that the crystal growth rate was ∼1.5 μm/min, at 520°C.

Ｇａ添加Ｎｄ‐Ｆｅ‐Ｂ系ＨＤＤＲ磁石粉末の磁気特性

The effect of Ga addition on the enhancement of coercivity in HDDR-treated Nd-Fe-B powders, was investigated. Microstructural observation revealed that Ga addition suppresses grain growth of recombined Nd2Fe14B during the DR process. Analysis using the microstructural parameters in Kronmmarüllers equation shows that the α K value of Ga-added samples (0.48) is larger than that of ternary samples (0.12), which suggests that Ga leads to the development of reduced surface anisotropy in the recombined Nd2Fe14B grains.

Thermodynamic calculation of the binary systems M-Ga and investigation of ternary M-Ga-N phase equilibria (M=Ni, Co, Pd, Cr)

A thermodynamic modeling of the binary systems Ni-Ga, Co-Ga, Pd-Ga, and Cr-Ga has been performed using the CALPHAD method. This modeling is focused on a simplified description of the solid-state equilibria. From published data on binary nitrogen systems, isothermal sections of the ternary M-Ga-N systems have been calculated by extrapolation. Ternary samples were prepared from M and GaN powders in various ratios, pressed to pellets, and annealed between 500 and 700 °C for up to 162 h. Phase analyses were carried out by x-ray diffraction, and the results compared to the calculated ternary phase equilibria; the comparisons indicate that M+GaN are not in equilibrium in any of these systems. Experimental results show that the M+GaN reactions are sluggish. In the ternary Ni-, Co-, and Pd-Ga-N systems, no ternary compounds were observed. The solid reaction products are essentially the metal-rich binary intermetallics (Ni3Ga, CoGa, Pd2Ga). Thermodynamic calculations show that, at elevated (local) pressure, reaction slows down. Pressure buildup must have occurred inside the tightly pressed pellet, since only small amounts of nitrogen gas were found to have escaped from the pellet. In the Cr-Ga-N system, two ternary compounds are known to exist along the Cr-GaN section. Therefore, the reaction of GaN with Cr to form the ternary phases could occur without gas liberation. Even this reaction is sluggish and was not completed in the samples investigated.

Lead free solder materials In–Sn–Zn system

We investigated the bulk as well as surface properties of the In–Sn–Zn system because of its potential as lead free solder materials. Differential thermal analysis X-ray and microprobe analysis were performed on forty ternary samples. Our X-ray investigation showed a single phase at 10 and 25 at.% Zn and two phases ( γ + Zn) at 40 and 55 at.% Zn. Quenched samples showed an invariant effect in γ + [Zn] solid solution. Heat treatment did not produce any effect on the ternary eutectic temperature. A statistical mechanical theory based on a layered structure has been used to develop expressions for the surface tension ( γ) and surface composition ( C s) in the frame-work of self-association and compound formation models. These expressions have been utilised to compute γ and C s of In–Sn and Sn–Zn systems as a function of concentration and temperature. Our study suggests an increase in γ of both (In–Sn and Sn–Zn) systems with the addition of In to Sn and Zn to Sn, respectively. It is interesting to observe that Sn atoms segregate to the surface of both the systems at all bulk compositions – with the larger extent of segregation in Sn–Zn. Segregation of Sn atoms and formation of di-atomic like atoms clusters (Sn 2) might be influencing the wetting and adhesion in solder joints.

High Verdet constant Ga:S:La:O chalcogenide glasses for magneto-optical devices

The magneto-optical rotation at room temperature was mea- sured for three Ga:S:La:O chalcogenide glasses at several laser lines in the visible. The first sample was a binary system constituted by 70 mol % Ga2S3 and 30 mol % La2O3, whereas in the second and third ones the lanthanum oxide was partially substituted by lanthanum sulfide, keeping the amount of gallium sulfide fixed. A pulsed magnetic field between 50 and 80 kG was used for the Faraday rotation measurements. The Verdet constant for one of the ternary samples was found to be as high as 0.205 min G 21 cm 21 at 543 nm, indicating that these chalcogenide glasses are very promising for magneto-optical applications. The data for each sample were fitted using the expected analytical expression for the magneto-optical dispersion. Measurements of the refractive index of the glasses at 632.8 nm are also reported. Data on the magneto-optical properties of two high Verdet constant, heavy-metal oxide diamagnetic glasses are also included for comparison. © 1999 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(99)00102-6)

Quenched GaTeFe alloys near the Ga 20Te 80 composition

Rapidly quenched samples of Ga–Te and Ga–Te–Fe were obtained from the liquid, with a piston and anvil device, in a composition near the Ga 6Te 94 eutectic. X-ray diffraction with Cu (K α) radiation and Mössbauer spectroscopy at room temperature with a 57Co (Rh) source were used to determine the structure of the samples. Either amorphous or partially amorphous structures were observed in the binary samples while partially amorphous structures with FeTe 2 precipitates were observed in the ternary samples. The glass forming tendency is analyzed by comparing the amount of amorphous phase and crystalline phases present in samples with and without iron.

Optical characterization of molecular beam epitaxially grown InAsSb nearly lattice matched to GaSb

Molecular beam epitaxially (MBE)-grown InAsSb nearly lattice matched to (001) GaSb substrates has been studied by infrared absorption, photoluminescence (PL), and double crystal x-ray diffraction (DCXRD). The absorption measurements, made at temperatures of 6–295 K, resulted in determinations of the temperature and compositional dependencies of the energy gap and the absorption coefficients for InAs1−xSbx (0⩽x⩽0.192). Temperature- and laser excitation power-dependent PL measurements showed only a single band edge peak for the ternary samples (Δa/a⩽+0.623%). Both low temperature PL linewidths (as narrow as 4.3 meV) and observations of LO-phonon replicas indicate the good quality of this material. However, careful analysis of the PL data indicates that even this good material may have a tendency for phase separation resulting in compositional inhomogeneity as reported previously for MBE-grown InAsSb. (004) DCXRD measurements resulted in lattice mismatches between −0.629%⩽Δa/a⩽+0.708% for these samples, while (115) DCXRD measurements indicated that tensile strain persisted in the epilayers, even for thicknesses up to 1.4 μm.

Raman study of photostructural changes in amorphous Ge xSb 0.4− xS 0.6

Raman spectra of amorphous Ge x Sb 0.4− x S 0.6 films and bulk samples have been measured for several values of x. The observed Raman bands are due to heteropolar M–S (M=Ge, Sb) bonds in the GeS 4 tetrahedra and SbS 3 pyramids, as well as homopolar (defective) M–M bonds whose population increases with increasing x. Illumination of Ge-rich ternary films by band gap light induces photostructural changes, the most prominent of which being an increase of the relative population of M–M to M–S bonds. At larger intensities of illumination (by laser light), partial crystallization of Sb occurs in both films and bulk glasses and, again, this photostructural effect is larger in Ge-rich ternary samples. It is revealed that the SbS 3 pyramidal population decreases after either of the above treatments, thus underlining the key role of the Sb–S bonds in the photostructural changes. Furthermore, the extent of these effects is discussed in terms of the defective bond population, the free volume and dimensionality of the glassy network.

A new ternary mixed oxide catalyst for ammoxidation of propane: Sn/V/Sb

The catalytic properties of a Sn/V/Sb mixed oxide for propane ammoxidation to acrylonitrile are studied in this paper. In particular the antimony and vanadium amounts were changed in order to optimize the relative atomic ratio. The ternary sample with the best catalytic performance was compared with the analogous binary samples (Sn/Sb and Sb/V). The results obtained indicate that vanadium is responsible for the paraffin activation, nevertheless much vanadium produces a lot of carbon oxides. Antimony is responsible for the insertion of nitrogen in the molecule (it can be considered as an acrylonitrile selectivity modulator); nevertheless, too much antimony deactivates the catalyst. Tin does not act only as a dispersive matrix for the active sites, but leads to the formation of a polyfunctional catalyst, increasing the rate of acrylonitrile formation from the intermediate propene. From a structural point of view, this catalytic system can be described as a homogeneous system, containing microfields of rutile type oxide (SnO2), promoted with antimony and vanadium in substitutional solid solution, dispersed in an excess of amorphous antimony oxide.

Selective Oxidation of Ethanol to Acetaldehyde on V2O5/TiO2/SiO2Catalysts

The effect of coating the SiO2support of a V2O5oxidation catalyst with different amounts of TiO2has been studied. X-ray photoelectron spectroscopy of the resulting V2O5/TiO2/SiO2showed that the highest dispersion was reached for the low TiO2coverages. The catalysts were prepared by depositing vanadia in a quantity equivalent to one monolayer onto SiO2, TiO2, or TiO2-coated SiO2samples, by impregnation with a vanadyl acetylacetonate solution in ethanol, drying at 348 K, and calcining at 773 K in air. This procedure decreased the surface area by up to 30%. TPR profiles of binary and ternary samples were similar, showing only a single peak, suggesting the presence of just one vanadium species. Electron spin resonance spectra of partially reduced TiO2-coated silica carriers showed that, at very low titania content, titanium ions were present in the silica surface in small clusters. In the high content sample, TiO2covered the silica surface, as in a crystalline TiO2phase. The characteristics of supported vanadium oxide were affected by the TiO2distribution. These V/xTiSi catalysts were found to be active for the selective oxidation of ethanol. The titania coating of the support increased the activity of the supported vanadia as compared to that of the oxide supported on silica, but maintained a similar product distribution. This increase of activity depended on the number of titania monolayers (x), being maximum forx≥1. The selectivity to acetaldehyde also increased withx, being maximum for the same composition. The combination of the two factors allowed the attainment of acetaldehyde yields of 74% per pass at temperatures as low as 473 K. The modifications in the catalytic behavior are discussed in terms of the changes of the support surface and its interaction with the supported vanadia caused by the presence of the titania coating.

Plastic deformation of uniaxially aligned lamellar γ/α 2 titanium aluminides containing chromium

Polysynthetically twinned uniaxially aligned lamellar binary and ternary γ/α 2 titanium aluminides were deformed in uniaxial compression and investigated in the transmission electron microscope. The yield stress strongly depends on the orientation of the lamellae to the compression axis. For all investigated orientations, the yield stress of the ternary samples containing chromium is higher than that of the corresponding binary material. The yield stress decreases with increasing temperature. The deformation is mainly carried by ordinary dislocations 〈110] and (twinning) partial dislocations 1/6〈112] which are still active at high temperatures. If the lamellar interfaces are oriented parallel to the compression axis, deformation twinning is the main deformation process.