bluuebunny/crossref_metadata_2025_split huggingface dataset:
Starch Properties in Different Lines of an old Hungarian Wheat Variety, Bánkúti 1201
Authors: Rakszegi Mariann , Batey Ian L. , Vida Gyula , Juhász Angéla , Bedő Zoltán , Morell Matthew K. 
Published: September 2003

AbstractThe old Hungarian wheat variety, Bánkúti 1201 was previously divided into lines on the basis of high molecular weight (HMW) glutenin subunit composition. In this work the starch properties of these lines were studied. The amylose contents of the lines ranged from 14.4% to 24.2%, which means a wide variation. The Rapid Visco Analyser (RVA) peak viscosity of the starch ranged from 232 to 372 Rapid Visco Units (RVU) and the enthalpy of gelatinisation (ΔH) measured by Differential Scanning Calorimetry (DSC) varied between 8.3 and 16.3 J/g. To study the relationship between the different lines on the basis of starch properties, Hierarchical Cluster Analysis was carried out based on RVA, DSC and HPLC results. Five groups of Bánkúti lines could be distinguished on the basis of these traits. According to the results, Bánkúti lines heterogeneous with respect to their HMW glutenin composition are also heterogeneous for their starch properties. Nevertheless, there was no correlation between the variability in protein composition and starch properties.
Reactivity in the System Copper/Arsenic/Sulfur II. The Formation of CuAsS, (Lautite)
Authors: Müller A. , Blachnik R. 
Published: September 2003

AbstractThe reaction pathways during the synthesis of CuAsS have been studied with the DTA in the range 25 — 810 °C with a heating rate of 10 K/min. Educts, intermediates, and products were characterized by X‐ray diffraction at room and elevated temperatures. Educts were the corresponding elements and the binary compounds As4S4, As2S3, Cu3—xAs, Cu5—δAs2, Cu2S, and CuS. The 13 examined educt mixtures can be divided into four groups specified by their thermal effects observed during the reaction. Mixtures of group I contain copper arsenides and arsenic sulfides, those of group II and III arsenic and copper sulfides, and arsenic sulfides and copper, respectively. Group IV includes mixtures showing individual reactions. In all cases the reaction to CuAsS proceeds stepwise. The reaction is not completed at 574 °C, the decomposition temperature of CuAsS, because the product is still associated with Cu12+xAs4+yS13 , As, and to a lesser amount with Cu1.81S. Nevertheless, a consecutive run in which the samples were heated above the liquidus temperature shows no exothermic reaction effect. When the mixtures were cooled at 10 K/min after the runs, no CuAsS was found in the X‐ray experiments. Only Cu12+xAs4+yS13 and As were then observed.
Investigations on Chemical Vapour Transport of Intermetallic Phases in the System Co/Fe/Si
Authors: Boldt R. , Reichelt W. , Bosholm O. , Oppermann H. 
Published: September 2003

AbstractThe ternary phases existing on the quasi binary section CoSi/FeSi and CoSi2/β‐FeSi2 have been investigated by solid state reactions and chemical transport. The solid solution serie CoxFe1‐xSi can be described as a regular solution. The transport behaviour calculated is in good agreement with the experiments. The phases have been characterized by X‐ray powder diffraction, EDX and ICP‐OES. The temperature dependence of the resistivity has been measured from 20 K up to room temperature on single crystals.
Kinetically Controlled Solid State Reactions in the System InCl/SnCl2
Authors: Beck H. P. , Kallmayer V. 
Published: September 2003

AbstractThis paper reports on studies on the reaction of InCl with SnCl2 to form ternary halides. The reaction route is investigated by x‐ray investigations at different temperatures. Depending on the modification of InCl as educt and on the temperature conditions the reaction follows different pathways which may include intermediate redox reactions of the type In+ + Sn2+ → In3+ + Sn0.
Nitridation of V5Al8 films with NH3 by Rapid Thermal Processing (RTP)
Authors: Lewalter H. , Kolbesen B. O. 
Published: September 2003

AbstractV5Al8 films (thickness about 100 nm) were deposited on sapphire substrates by RF‐sputtering and nitridated with NH3 at 600‐1250 °C (1 min) in a RTP system. The as deposited and nitridated films were investigated by ESCA (electron spectroscopy for chemical analysis), XRD (X‐ray diffraction), XRR (X‐ray reflectometry), AFM (atomic force microscopy) and SEM (scanning electron microscopy). Formation of an aluminum nitride layer at the surface and precipitation of V(Al) in the bulk was found. In the temperature regime from 600 °C to 900 °C a considerable amount of oxygen is incorporated in the aluminum nitride layer. The roughness of the surface increased with increasing temperature and at 1250 °C a partially detaching of the AlN layer could be observed.
Preparation, Crystallographic, Spectroscopic and Magnetic Characterization of Low‐Valency Nitridometalates Li2[(Li1‐xMx)N] with M = Cu, Ni
Authors: Niewa R. , Huang Z.‐L. , Schnelle W. , Hu Z. , Kniep R. 
Published: September 2003

AbstractThermogravimetric and difference thermal analyses show that the reactions of lithium nitride with the transition metals Cu and Ni under molecular nitrogen to form phases Li2[(Li1‐xMIx)N] take place above 673 K. The maximum weight gains are reached at 926 K and 968 K for M = Cu and Ni, respectively. At higher temperatures, the ternary phases Li2[(Li1‐xMIx)N] decompose, limiting the substitutional level x. In the temperature range of 773 K — 873 K, the successful synthesis of Li2[(Li1‐xNiIx)N] (0 < x ≤ 0.85(1)) single phase products is demonstrated. Maximum substitution obtained for the Cu phases is xmax= 0.43(1). The dependence of the lattice parameters of the hexagonal unit cell on x is almost linear. The magnetic moment of M strongly depends on x. At low x the magnetic moments in phases with M = Ni are presumably enhanced by orbital effects. A decrease of μeff with x to μeff(x = 1) → 0 is explained by delocalization of the magnetic moments and by the gradual formation of a metal for the hypothetical compound Li2[NiN] (x = 1). XAS spectroscopy at the transition metal K‐edges shows that Cu and Ni principally correspond to d10‐ and d9‐configurations, respectively.
Nucleation of CuGa Phases on the MgO(100) Surface
Authors: Geudtner Gerald , Jug Karl 
Published: September 2003

AbstractMSINDO calculations are presented for the coadsorption of Cu and Ga atoms as clusters and islands on the MgO(100) surface. The surface is simulated by a (8 × 8 × 3) Mg96O96 cyclic cluster. The relative number of Cu and Ga atoms was varied in order to understand the influence of copper rich and gallium rich phases. It was found that the copper atoms have a dominating influence on the structural arrangement in mixed phases. The adsorption sites of Cu and Ga atoms are preferably O atoms, but in mixed phases these sites are usually occupied by Cu atoms.
Theoretical Investigation of the Solid State Reaction of Silicon Nitride and Silicon Dioxide forming Silicon Oxynitride (Si2N2O) under Pressure
Authors: Kroll Peter , Milko Matus 
Published: September 2003

AbstractThe high‐pressure behavior of Si2N2O is studied for pressures up to 100 GPa using density functional theory calculations. The investigation of a manifold of hypothetical polymorphs leads us to propose two dense phases of Si2N2O, succeeding the orthorhombic ambient‐pressure polymorph at higher pressures:a defect spinel structure at moderate pressures and a corundum‐type structure at very high pressures. Taking into account the formation of silicon oxynitride from silicon dioxide and silicon nitride and its pressure dependence, we propose five pressure regions of interest for Si2N2O within the pseudo‐binary phase diagram SiO2‐Si3N4: (i) stability of the orthorhombic ternary phase of Si2N2O up to 6 GPa, (ii) a phase assemblage of coesite, stishovite, and β‐Si3N4 between 6 and 11 GPa, (iii) a possible defect spinel modification of Si2N2O between 11 and 16 GPa, (iv) a phase assemblage of stishovite and γ‐Si3N4 above 40 GPa, and (v) a possible ternary Si2N2O phase with corundum‐type structure beyond 80 GPa. The existence of both ternary high‐pressure phases of Si2N2O, however, depends on the delicate influence of configurational entropy to the free energy of the solid state reaction.
Chemical Reactivity of Tetrasulfur Tetranitride: Synthesis, Physical Properties, and Structural Characterization of the Amorphous Phase Cu7S4N4
Authors: Irsen Stephan H. , Kroll Peter , Dronskowski Richard , Weirich Thomas E. , Epple Matthias 
Published: September 2003

AbstractTetrasulfur tetranitride, S4N4, reacts with elemental Cu within inert solvents to a black‐blue material of approximate composition Cu7S4N4 which is totally amorphous to X‐rays and which cannot be made crystalline by either thermal treatment or electron radiation. Cu7S4N4 explodes if heated above 234 °C or when subjected to mechanical shock to eventually yield copper(I) sulfide; this together with the characteristic infrared spectrum of Cu7S4N4 indicates the presence of molecular S4N4 units inside the amorphous phase. The metastable nature of Cu7S4N4 is also mirrored by electron microscopy which furthermore allows the structural characterization of its degradation products. Based on experimental EXAFS data offering characteristic Cu—N and Cu—S distances, a theoretical crystalline approximant of Cu7S4N4 was suggested and structurally optimized by density‐functional total‐energy calculations including periodic boundary conditions. This model incorporates a central S4N4 unit bonded to three shells of Cu atoms of different functionalities; in addition, a partial rupture of the S4N4 unit is likely to allow for a lowering of the total energy of the metastable phase. The latter observation supports the impossibility to make Cu7S4N4 crystallize using 4N4 crystallize using whatever kind of measures.
Alkaline Metal Stannide‐Stannates: ‘Double Salts’ with Zintl Sn and Stannate SnO Anions
Authors: Frisch Gero , Hoch Constantin , Röhr Caroline , Zönnchen Peter , Becker Klaus‐Dieter , Niemeier Dirk 
Published: September 2003

AbstractUsing the reduction of tin oxides with the elemental alkaline metals rubidium and cesium, stannide stannates have been synthesized which contain Zintl anions [Sn4]4— (i.e. Sn—I) and isolated oxostannate ions [SnO3]4— (i.e. Sn+II) together with further oxide ions for charge compensation. The crystal structures of the three compounds A23.6Sn7.4O13.2 = A23.6[Sn4][SnO3]3.4[O]3 (A = Rb 1a: monoclinic, P21/c, a = 2174.2(6), b = 1137.0(6), c = 2373.6(6) pm, β = 116.11(2)°, Z = 4, R1 = 0.056; A = Cs 1b: monoclinic, P21/c, a = 2042.6(6), b = 1185.4(3), c = 2481.1(7) pm, β = 97.06(2)°, Z = 4, R1 = 0.075) and Cs48Sn20O21 = Cs48[Sn4]4[SnO3]4[O]7[O2] (2 monoclinic, P2/c, a = 1701.8(3), b = 877.4(2), c = 4556.9(7) pm, β= 101.47(1)°, R1 = 0.093) have been determined on the basis of single crystal data. The transparency of the compounds allowed the recording of raman spectra of the anion [Sn4]4—. The 119Sn Moessbauer spectrum of the rubidium compound shows a singulet in good agreement with RbSn, overlapping a doublet caused by Sn2+ in the asymmetrical environment of the strongly electronegative oxygen ligands of SnO.
Shape Controlling Synthesis — Formation of Fe3Si by the Reaction of Iron with Silicon Tetrachloride and Crystal Structure Refinement
Authors: Schütte M. , Wartchow R. , Binnewies M. 
Published: September 2003

AbstractPure Fe3Si is formed by the reaction of an iron‐wire with SiCl4‐vapor at a reaction temperature of 1000 °C and a SiCl4‐pressure of 2 bar. Remarkable is the fact that the outer shape of the used iron wire has not been changed during the reaction. The crystal structure of Fe3Si was determined using single crystal methods. Fe3Si crystallizes in the space group Fm3m. The lattice parameters depend on the composition.
Reactivity, Syntheses, and Crystal Structures of Na5[MO2][X] with M = Co+, Ni+, Cu+; X = CO32—, SO42—, SO32—, S2—, and Na25[CuO2]5[SO4]4[S]
Authors: Amann Peter , Möller Angela 
Published: September 2003

AbstractNa5[CuO2][CO3], Na5[CuO2][SO3], Na5[CuO2][S], and Na5[CuO2][SO4] were obtained as single crystals and powders from reactions of Na2O, Cu2O, and Na2X with X = CO32—, SO32—, S2—, and SO42—, respectively. A redox reaction between CdO and Co metal occurs in the presence of Na2O and Na2X, yielding Na5[CoO2][X] with X = CO32— and S2—. From a mixture of Na2SO4, CdO and Na2O in Ni‐containers we observed the formation of Na5[NiO2][S] single crystals. Single crystals of Na25[CuO2]5[SO4]4[S] can be grown by annealing Na5[CuO2][SO3] at 600 °C, leading to the decomposition of SO32—, yielding SO42— and S2— at 550 °C. The structures have been determined from single crystal data and powder data. All structures contain the isolated complex [MO2]3— in a dumb‐bell like arrangement. The main feature of these compounds is that the anions SO42—, SO32—, CO32— and S2— are not connected to the transition metal. The formation of Na5[CuO2][X] (X = S2—, SO42—, SO32—, CO32—) has been studied by thermal analysis and in situ X‐ray diffraction techniques. Infrared spectra confirm the presence of SO42—, SO32—, and CO32—, respectively, in the structures.
The Reactivity of Cr‐Te Superlattice Reactants and of Co‐deposited Cr‐Te Films: Studies with in‐situ X‐ray Diffractometry
Authors: Herzog Sabine , Kraschinski Sven , Bensch Wolfgang 
Published: September 2003

AbstractThe reactivity of a Cr‐Te multilayer film consisting of 326 Cr/Te double‐layers with about 88(3) at% Te was investigated with in‐situ X‐ray diffraction. The occurrence of a superstructure reflection caused by the multilayer system is observed. During the annealing procedure between 80 and 90 °C the layer‐by‐layer arrangement is destroyed and elemental Te crystallizes. After 6 h isothermal annealing at 140 °C CrTe3 starts to crystallize. The amount and the crystal size of CrTe3 increase with raising temperature and Te is consumed during the growth process. At 220 °C the formation of crystalline Cr2Te3 is observed and between 220 and 260 °C CrTe3 is completely decomposed into Cr2Te3. The two Cr tellurides grow as highly textured materials. The size of CrTe3 crystals is significantly larger than that of Cr2Te3. For a co‐deposited Cr‐Te film with composition 77(3) at% Te the tri‐telluride and elemental Te crystallize simultaneously. The texture of CrTe3 is less pronounced and different reflections of the tri‐telluride occur besides the (h00)‐reflections. Up to 160 °C a pronounced increase of the crystallite size is observed and the crystals are significantly larger than those obtained with the multifilm sample. At 130 °C the crystallization kinetics seem to be controlled by nucleation.
Vanadium Nitride Films Formed by Rapid Thermal Processing (RTP): Depth Profiles and Interface Reactions Studied by Complementary Analytical Techniques
Authors: Berendes A. , Galesic I. , Mertens R. , Bock W. , Oechsner H. , Warbichler P. , Hofer F. , Theodossiu E. , Baumann H. , Kolbesen B. O. 
Published: September 2003

AbstractThe nitridation of vanadium films in molecular nitrogen and ammonia using a RTP‐system was investigated. The V films were deposited on silicon substrates covered by 100 nm thermal SiO2. For a few experiments sapphire substrates were used. Nitride formation at high temperatures (900 and 1100 °C) and interface reactions and diffusion of oxygen out of the SiO2‐layer into the metal lattice at moderate temperatures (600 and 700 °C) were studied. For characterisation complementary analytical methods were used: X‐ray diffraction (XRD) for phase analysis, secondary neutral mass spectrometry (SNMS) and Rutherford Backscattering (RBS) for acquisition of depth profiles of V, N, O, C and Si, transmission electron microscopy (TEM) in combination with electron energy filtering for imaging element distributions (EFTEM) and recording electron energy loss spectra (EELS) to obtain detailed information about the initial stages of nitride, oxide and oxynitride formation, respectively, and the microstructure and element distributions of the films. In these experiments the SiO2‐layer acts as diffusion barrier for nitrogen and source for oxygen causing the formation of substoichiometric vanadium oxides and oxynitrides near the V/SiO2‐interface primarily at temperatures ≤ 900 °C. At a temperature of 1100 °C just a small amount of oxynitride forms near the interface because rapid diffusion of nitrogen and fast formation of VN (diffusion barrier for oxygen) inhibit the outdiffusion of oxygen into the metal layer. In the 600 °C regime, in argon atmosphere oxynitride phases observed in the surface region of these films originate from reaction of residual oxygen in the argon gas, whereas NH3 as process gas does not lead to oxide or oxynitride formation at the surface (apart from the oxidation caused by storage). NH3 seems to support the diffusion of oxygen out of the SiO2‐layer. During the decomposition of ammonia at higher temperatures hydrogen is formed, which could attack the SiO2. In contrast, sapphire substrates do not act as oxygen source in the 600 °C regime and change the nitridation behaviour of the vanadium films.
Solid State Metathesis Reactions in Various Applications
Authors: Gibson Katharina , Ströbele Markus , Blaschkowski Björn , Glaser Jochen , Weisser Martina , Srinivasan Radhakrishnan , Kolb Heinz‐Jürgen , Meyer Hans‐Jürgen 
Published: September 2003

AbstractSolid state metathesis reactions have been studied in fused silica tubes, by differential thermal analysis, and by X‐ray powder diffraction. A selection of reactions between metal (La, Nb, and Ni) chlorides and lithium nitride or lithium acetylide were investigated to get more insight into reaction pathways and intermediate reaction stages that may be adopted on course of the formation of metal nitrides or carbides. Intermediate compounds are considered to be important because they can control the reactivity of a system. Such compounds were traced by changing the molar ratios of reaction partners away from the salt‐balanced binary metal nitride or carbide target compositions.New preparative perspectives are discovered when metal chlorides were reacted with lithium nitridoborate or lithium cyanamide. Due to their reductive nature towards several d‐block metal chlorides, (BN2)3‐ and (CN2)2‐ react to form metals or metal nitrides plus X‐ray amorphous BN, and probably C3N4. With lanthanum chloride they can react to form nitridoborates and nitridocarbonates. The metathesis reaction between lithium cyanamide and cyanuric chloride (C3N3Cl3) instead of metal chloride was studied for the synthesis of C3N4.
Investigations of Reactivity and Magnetic Properties of Nanostructured Iron Oxide within Mesoporous Silica Materials
Authors: Köhn Ralf , Fröba Michael 
Published: September 2003

AbstractThe change in reactivity for nanostructured iron oxide within mesoporous silica materials is demonstrated. Iron oxides were incorporated into the pore system of MCM‐41 and MCM‐48 silica materials and characterized by powder X‐ray diffraction and nitrogen physisorption. Iron oxide shows significant changes in the reducibility by hydrogen compared to comparable bulk iron oxide phases. Partially reduced iron oxides within the mesoporous host were characterized by X‐ray absorption spectroscopy and SQUID measurements.
Contributions on Thermal Behaviour and Crystal Chemistry of Anhydrous Phosphates. XXXIV [1] Oxygen Equilibrium Pressures in Ternary Systems M / P / O (M = Co, Ni) and Heats of Formation of Anhydrous Cobalt(II) and Nickel(II) Phosphates
Authors: Blum Matthias , Teske Klaus , Glaum Robert 
Published: September 2003

AbstractOxygen equilibrium pressures have been measured in the temperature range 800 °C to 1000 °C by coulometric/potentiometric techniques for several equilibrium regions in the ternary systems M / P / O (M = Co, Ni). In both systems oxygen coexistence pressures of three‐phase equilibrium solids phosphide/phosphate are about 3 to 5 orders of magnitude smaller than p(O2) above the corresponding Ms / MOs system.Heats of formation ΔfH°298 and standard entropies S°298 for the phosphates have been obtained from 2nd and 3rd law evaluation of the temperature dependence of the oxygen coexistence pressures. Thermodynamic data from literature for the phosphides of cobalt and nickel and estimated heat capacities for the anhydrous phosphates Co3(PO4)2, Co2P2O7, Ni3(PO4)2, Ni2P2O7 and Ni2P4O12 were used for these calculations. Thus obtained enthalpies and entropies are compared to results from thermodynamic modelling of observed solid phase equilibria in the ternary systems M / P / O (M = Co, Ni).
Surface Core Level Shifts of Yb Films in the Multilayer, Monolayer and Submonolayer Range
Authors: Müller F. , Stöwe K. 
Published: September 2003

AbstractSurface core level shifts in Yb and other rare earth elements, as well as in their compounds, arise from a reduced band width of the 5d band, caused by the reduced coordination at surface sites, with the strength and direction of the shifts depending on the occupation of the 5d band. If the coordination, or more exactly, the local symmetry is considered to be the decisive factor for changing the band width, it is obvious to look for core level shifts even at the interface of two solids. In order to investigate such interface core level shifts, thin Yb films of thicknesses from the multilayer down to the submonolayer range, grown on a polycristalline W substrat, were investigated by photoelectronspectroscopy. It was found, that for decreasing film thicknesses, the ratio of the surface to bulk related 4f intensities increases systematically, and finally, for thicknesses of one up to two monolayers, only the broad, surface related part of the Yb 4f doublet can be observed. For Yb coverages fewer than one monolayer, there is a sudden shift of this remaining doublet towards the Fermi energy, which must result from a reduced occupation of the Yb 5d band due to an electron transfer from Yb to W at the interface.
The Oxidation of Heterogeneous Tl/Ni/P‐Alloys — Preparation and Crystal Structures of the Thallium Nickel Phosphates TlNi4(PO4)3, Tl4Ni7(PO4)6, and Tl2Ni4(P2O7)(PO4)2
Authors: Panahandeh Ahmad , Jung Walter 
Published: September 2003

AbstractSingle crystals of the first anhydrous thallium nickel phosphates were prepared by reaction of heterogeneous Tl/Ni/P alloys with oxygen. TlNi4(PO4)3 (pale‐yellow, orthorhombic, space group Cmc21, a = 6.441(2)Å, b = 16.410(4)Å, c = 9.624(2)Å, Z = 4) crystallizes with a structure closely related to that of NaNi4(PO4)3. Tl4Ni7(PO4)6 (yellow‐brown, monoclinic, space group Cm, a = 10.711(1)Å, b = 14.275(2)Å, c = 6.688(2)Å, β = 103.50(2)°, Z = 8) is isotypic with Na4Ni7(PO4)6, and Tl2Ni4(P2O7)(PO4)2 (brown, monoclinic, space group C2/c, a = 10.389(2)Å, b = 13.888(16)Å, c = 18.198(3)Å, β = 103.1(2)°, Z = 8) adopts the K2Ni4(P2O7)(PO4)2 structure. Tl2Ni4(P2O7)(PO4)2 could also be prepared in nearly single phase form by reaction of Tl2CO3, NiO, and (NH4)2HPO4.
In Situ Study of the Surface Oxidation of FeCr Alloys Using Grazing Incidence X‐ray Absorption Spectroscopy (GIXAS)
Authors: Janssen Joachim , Rumpf Holger , Modrow Hartwig , Rablbauer Ralf , Frommeyer Georg , Hormes Josef 
Published: September 2003

AbstractThe surface oxidation of FeCr alloys with 18, 28, and 43 mass‐% Cr was investigated in situ using grazing‐incidence X‐ray absorption spectroscopy (GIXAS) at the chromium and iron K‐edges. Oxidation in air was monitored in situ in the temperature range from 290 K to 680 K. The standard GIXAS data analysis is extended for the treatment of a single layer model in order to estimate the chromium concentrations of the oxide layer and of the near‐interface substrate as well as the oxide layer thickness. XANES analysis shows transitions from b.c.c. Fe to corundum type Fe2O3 and from b.c.c. Cr to corundum type Cr2O3. The initial oxide layers are 1.1‐1.4 nm thick and contain 60‐90 mass‐% chromium, while the near‐interface substrate is depleted in Cr. During heating, iron oxide growth dominates up to 560‐600 K. Then the chromium oxide layer loses its passivation effect and Cr oxidation sets in.