Der chemische Transport von Nickel mit Indiumjodid

Chemical Transport of Nickel by Indium Iodide At higher temperatures (1273 → 1073 K) the chemical transport of nickel by means of indium iodide going into the zone with lower temperature is caused by the endothermic reaction Ni + InJ₃O,_g = NiJ₂,_g + InJ_,g At lower temperatures (873 → 973 K) this reaction is superimposed by the formation of gas complexes. These exothermic reactions cause transport in the inversed direction.     

Der chemische Transport von Lanthanphosphat LaPO4 mit Br-haltigen Systemen

The chemical transport of LaPO₄ (1400 → 1200°K) is discussed on a thermodynamical basis and experimentally checked. Br₂ + PBr₃ used as transport agents give good transportrates. Br₂ + CO and Br₂ + C are also suitable transportsystems. On the other hand Br₂ without additions, caused by an unfavourable equilibrium position gives no measurable LaPO₄-transport. Using HBr as transport agent, the transport rate is small. In addition there are difficulties, caused by the partial decomposition of HBr into the elements and the diffusion of H₂ through the wall of the quartz ampoule. LaPO₄-crystals prepared by chemical transport have the well known monoclinic monazite structure.     

Der chemische Transport von Kupfergermaniden und Kupfersiliciden

Chemical Vapor Transport of Intermetallic Systems. 9 Chemical Transport of Copper Germanides and Copper Silicides By means of chemical vapor transport using iodine and bromine as transport agents in the system Cu/Ge the compounds Cu₃Ge (ϵ and ϵ₁), Cu₅Ge (ζ) and copper‐rich mixed crystals Cu(Ge) have been prepared in form of single crystals. Thermodynamic considerations allow to understand the CVT process, especially the unexpected low temperatures. Copper silicides can be prepared under similiar conditions. They are extremely disordered. Their crystallographic characterisation was therefore impossible.     

Der chemische Transport von Titangermaniden

Chemical Vapor Transport of Intermetallic Systems. 8. Chemical Transport of Titaniumgermanides By means of chemical vapor transport using iodine as transport agent in the System Ti/Ge the compounds TiGe₂ and Ti₅Ge₃ have been prepared in form of single crystals. Unexpectedly the phase Ti₆Ge₅ could not be deposited from the vapor phase. The experiments show in contrast to the literature that Ti₆Ge₅ is at 700 °C thermodynamic unstable. Chemical vapor transport is a suitable method to determine coexistence conditions of intermetallic compounds.     

Der chemische Transport von Platin mit Chlor. Experimentell bearbeitet mit Marita Trenkel

The Chemical Transport of Platinum with Chlorine Experiments show that the chemical transport of platinum by means of chlorine within a temperature gradient at temperatures below ≈ 1000°K goes into the hot temperature region, but at higher temperatures in the reverse direction. From the thermodynamic discussion it can be seen, that the platinum content of the gas phase at low temperatures is governed by the exothermic formation of Pt₆Cl_12,g, and at higher temperatures by the endothermic formation of PtCl_3,g and PtCl_2,g. The platinum content of the gas phase passes a minimum at ≈ 1000°K, if P(Cl₂) = 3.5 atm. This result is in agreement with the observed inversion of the transport direction.     

Zum chemischen Transport von Vanadiummonophosphid mit lod

Chemical transport of vanadiummonophosphide with iodine Well shaped crystals of vanadiummonophosphide can be grown by CVT using iodine as transport agent (e. g. → 900°C). As a result of thermodynamical calculations the evaporation and deposition of VP should be expressed by the following exothermic equilibrium At higher temperatures and low concentrations of Iodine, combined with desorption of moisture from the walls of the silica ampules endothermic deposition of VP according to has been observed. Assuming Δ_BH°₂₉₈(VP_s) = ?61 [kcal/mol] a satisfying agreement between thermodynamical calculations and experimental results can be reached.     

Chemischer Transport intermetallischer Phasen. 4. Der chemische Transport von Co5Ge3 und CoGe

Chemical Vapor Transport of Intermetallic Systems. Chemical Transport of Co₅Ge₃ and CoGe By means of transport reaction (900 → 700°C, Iodine as transport agent) pure Co₅Ge₃ or Co₅Ge₃ with CoGe as a by-product can be prepared. Thermodynamic calculations allow to understand the reaction semiquantitatively.     

Der chemische Transport des Silbers mit Jod und die Umkehrung der Transportrichtung im Temperaturgefälle

The Chemical Transport of Silver with Iodine and the Inversion of the Transport Direction in the Temperature-Gradient The formation of Ag₃I_3,g from Ag_,s and I_,g is exothermic, the corresponding formation of AgI_,g is endothermic. Depending on the temperature one expects chemical transport of Ag into the higher or the lower temperature region. This inversion of the transport direction has been calculated thermodynamically and experimentally observed.     

Chemischer Transport intermetallischer Phasen. 5 [1]. Der chemische Transport von Ni3Sn und Ni3Sn2

Chemical Vapor Transport of Intermetallic Systems. 5. Chemical Transport of Ni₃Sn and Ni₃Sn₂ The congruent melting intermetallic compounds. Ni₃Sn and Ni₃Sn₂ can be prepared by CVT-methods using Iodine as transport agent. Thermodynamic calculations allow to understand why Ni₃Sn and Ni₃Sn₂ but not Ni₃Sn₄ can be prepared by this manner. Some general rules concerning CVT of intermetallics are given.     

Der Chemische Transport von Sb2S3 mit J2

The Chemical Transport of Sb₂S₃ With I₂ The chemical transport of Sb₂S₃ with iodine is discussed on thermodynamical basis under consideration of the gaseous molecules I₂, I₁, SbI₃, S₂, S₃, S₄, S₅, S₆, S₇ and S₈. The experiments are in a satisfying agreement with the calculations.     

Das Massenspektrum des Systems Te/S und der chemische Transport von Tellur mit Schwefel

Mass Spectrum of the System Te/S and the Chemical Transport of Tellurium with Sulphur The mixed molecules TeS_x (x = 1 … 7) and Te₂S_y (y = 1 … 6) have been observed by mass spectrometry. These molecules are responsible for the fact, that Tellurium can be chemically transported by means of sulphur in a temperature gradient (375 → 325°C).     

Beiträge zur Chemie der Oxidhalogenide von Molybdän und Wolfram. IV. Der Transport von MoO2 mit J2 und die Existenz von MoO2J2

The possibility to transport MoO₂ with J₂ in a temperature gradient T₂/T₁ suggests the existence of MoO₂J₂. Starting from the reaction MoO₂ + J₂ ? MoO₂J₂ in the consideration of the function of temperature for the rates of chemical transport, the values ΔH^O_R ? 28.8 (±2) kcal/mole and ΔS^O_R ? 9.0 (±2) cl are deduced. From this the values ΔH^O(MoO₂J₂, g, 298) ? ?99.5 (±3.5) kcal/mole and S^O(MoO₂J₂, g, 298) ? 86 (±3) cl are derived. The comparison of the thermodynamic data for MoO₂X₂ and WO₂X₂ (X = Cl, Br, J) leads to the conclusion, that the existence of MoO₂J₂ in the vapour phase is very probable indeed.     

Der chemische Transport der Phase CoS

The Chemical Transport of the CoS phase The CoS_x Phase can be deposited as single crystals by CTR using iodine, only if x is greater than 1.06. This is due to the sulphur phase equilibrium pressure which otherwise is too small for effecting this transport. HI or GeI₂ can be used as transport agent for specimens with less sulphur contents. Using GeI₂ CTR also yields monocrystals of the Co₉S₈ phase.     

Chemischer Transport intermetallischer Phasen Der chemische Transport von Mischkristallen im System Cu/Ag

Chemical Vapor Transport of Intermetallic Systems Chemical Transport of Cu/Ag-mixed Crystals By means of chemical transport reaction it is possible to prepare Cu-rich and Ag-rich mixed crystals in the Cu/Ag system. The composition of individual deposited crystals was different. Mass-spectrometric analysis of the gas-phase above CuI/AgI has shown the formation of CuAg₂I_3,g und Cu₂AgI_3,g. Thermodynamic computations explain the formation of crystals as well as the reaction conditions.     

Zum chemischen Transport von ZrO2 und HfO2 mit den Transportmitteln Cl2 und TeCl4

On the Chemical Transport of ZrO₂ and HfO₂ with the Transport Agents Cl₂ and TeCl₄ ZrO₂ und HfO₂ migrate in a temperature gradient (1100 → 1000°C) with the transport agent either Cl₂ or TeCl₄ by endothermic transport reaction. At experiments in silica glass tubes with TeCl₄ well developed crystals of ZrO₂ could be obtained. From HfO₂, as from both oxides using Cl₂, only powdery products are formed. The transport rates with TeCl₄ were higher than with Cl₂. The influence of different pressures was examined for the transport of ZrO₂ with TeCl₂ with thermochemical model calculations the expected transport rates could be investigated. The large correspondence between calculated and experimental received values speaks for a true interpretation of the transport observations.     

Der Transport von VO2 mit Cl2 und HCl + Cl2 und der Einfluß des O2-Bodenkörpergleichgewichtsdruckes auf den Transport

The Chemical Transport of VO₂ with Cl₂ and HCl + Cl₂ and the Influence of the O₂-Coexistence Equilibrium Pressure on the Transport Behaviour The transport behaviour of VO₂ with Cl₂, HCl, and Cl₂ was calculated and compared with the experimental results. VO₂ with the upper phase boundary transports with HCl and HCl + Cl₂ from the colder to the hotter zone, VO₂ of the lower phase boundary does not transport with HCl. The composition of the deposited VO₂ is near the upper boundary oxygen richer than in the start space. VO₂ does not transport with Cl₂.     

Der Nachweis von Indium mit Morin und von einigen Schwermetallen mit Kakothelin

Zusammenfassung Morin liefert mit Aluminium-, Gallium-, Scandium- und Indiumsalzen grün fluoreszierende Verbindungen von verschiedener Beständigkeit. Durch Einhaltung bestimmter Versuchsbedingungen (Zusatz von Alkalifluorid, Ammoncarbonat, Ammontartrat oder Schwefelwasserstoff) ist es möglich, die genannten Elemente auch nebeneinander durch eine Reaktion mit Morin zu erkennen. Die Erfassungsgrenze für den Indiumnachweis im ultravioletten Licht beträgt 0,02 In.Es wird gezeigt, daß die Reduktion von Kakothelin außer durch Zinn(II)-Salze noch durch Titan(III)-, Uran(III)-, Rhenium(III)-Salze, durch niedere Molybdän- und Wolframoxyde sowie durch Niob(III)-Chlorid herbeigeführt wird, wobei die Erfassungsgrenzen etwa 1 des betreffenden Metalles betragen.

---

Summary Morine reacts with aluminium, sodium, gallium, scandium, and indium salts, thus forming compounds of a green fluorescence colour and different stability. It is possible to recognize the elements mentioned, even in the presence of each other, by a morine reaction carried out under defined experimental conditions (i. e. addition of alkali fluoride, ammonium carbonate, ammonium tartrate, or sulphide of hydrogen). The limit of identification of indium in ultra-violet light is 0,02 In.It is shown that reduction of cacothelin is effected not only by tin (II) salts but also by titanium (III), uranium (IV), rhenium (III) salts, low oxydes of molybdene and tungsten, and by columbium (III) chloride, the limits of identification being about 1 of the metal in question.

---

Rèsume La morine fournit avec des sels d'aluminium, de gallium, de scandium et d'indium des combinaisons à fluorescence verte, différemment stables. En observant exactement certaines conditions de travail (addition de fluoride d'alcali, de carbonate d'ammonium, de tartrate d'ammonium ou d'hydrogène sulfuré), il est même possible, de reconnaître les éléments mentionnés, l'un à côté de l'autre à l'aide d'une réaction de morine. Dans la lumière ultraviolette, il est possible, de déceler jusqu'à 0,02 d'indium.L'auteur montre, que la réduction de la cacothéline peut être amenée, de même que par les sels d'étain, par le titane (III), l'urane (III), le rhénium (III), ainsi que par des oxydes de molybdène et de tungstène et par le chlorure de niobium. On peut déceler jusqu'à 1 du métal cherché.

     

Chemischer Transport intermetallischer Phasen. 2 [1]. Der chemische Transport von Mischkristallen im System Co/Ni

Chemical Vapor Transport of Intermetallic Systems. 2. Chemical Transport of Co/Ni-mixed Crystals By means of chemical transport reaction it is possible to prepare Co/Ni-mixed crystals in a wide range of percentage composition between 5 and 75 weight % Nickel. This is possible using a 3-zone-oven. Thermodynamic considerations allow to understand the experiments.     

Untersuchungen zur Kristallisation von Rhodium(III)-Oxoverbindungen unter Beteiligung der Gasphase – Der chemische Transport von Rh2O3 mit Chlor

Investigations on the Crystallization of Rhodium(III) Oxo Compounds – Chemical Vapour Transport of Rh₂O₃ using Chlorine Rh₂O_3,s migrates in chemical transport experiments with chlorine as transport agent from the higher (T₂) to the lower (T₁) temperature of a gradient (Δ_T = 100°) due to endothermal reactions (900°C < T ≤ 1050°C; T = 0,5 · (T₂ + T₁)). Under the conditions of transport experiments RhCl_3,s is observed in most experiments as equilibrium solid besides the sesquioxide. The transport rates for Rh₂O_3,s and the sublimation rates for RhCl_3,s grow with increasing temperature T . The composition of the equilibrium solids, the rates of migration and the sequence of deposition (1. RhCl_3,s, 2. Rh₂O_3,s) is well reproduced by thermodynamic model calculations. As a result of this calculations the transport behaviour of the system Rh₂O_3,s/Cl₂ is determined by the two equilibria The influence of RhCl_2,g and RhCl_4,g on the transport behaviour of Rh₂O_3,s as well as the possible occurence of RhOCl_2,g in the equilibrium gas phase will be discussed. Predictions of the transport behaviour of ternary rhodium(III) oxo compounds will be made.