X-ray powder diffraction investigations of solid solutions in the KCl?KBr?H2O system at 298 K

The measurements of crystal lattice parameters (a) of solid solutions being formed in the system KCl KBr H₂O at 298 K were conducted. The volumes (v) of unit cells and the densities (ϱ) of mixed crystals K(Cl, Br) were calculated. It was confirmed that in the investigated system continuous solid solutions were formed. The lattice parameters of these crystals formed from aqueous solutions of salts as well as from molten salts and also calculated by Durham-Hawkins method were nearly identic.     

Investigations of phase relations in the system CaO?Na2O?K2O?P2O5

The lattice constants of the compound Ca₂NaK(PO₄)₂ have been studied at room temperature using an X-ray powder diffractometer and also in the temperature range from 20 up to 1000 °C by Guinier-Lenné-technology. A hexagonal lattice with the parameters a₀ = 5.4367 Å and c₀ = 7.3125 Å and a cell volume of 187.18 ų has been determined for the high temperature phase, existing from 670 °C upward. At temperatures below 670 °C a superlattice structure is formed by tripling the axis a, a ′, and c so that it results in a hexagonal superlattice structure cell with the lattice constants of a₀ = 16.311 Å and c₀ = 21.939 Å and a cell volume of 5054 ų.     

Synthesis of AgI?AgCl?CuI solid solutions for ice nucleation studies

Lattice parameter calculation and the nucleation temperature of AgI AgCl CuI system are reported in this study. By vacuum fusion three samples of different molar compositions were prepared. The formation of the cubic solid solution of the above system was confirmed by X-ray analysis. It is found that the 50:25:25 mole% composition of AgI AgCl CuI has the highest nucleation temperature of −1.0 °C, which is far greater than −2.53 °C, −4.02 °C and −2.26 °C for pure AgI, AgCl, and CuI, respectively.     

Stabilization of the melt composition in Ga?Al?Sb?As

In this work we present a new effect of stabilization of the Ga Al Sb As melt composition when it is in contact with the GaAs substrate. It was found that the As content in the Ga Al Sb As melt did not depend on the initial Sb concentration when the liquid phase was formed by saturating the Ga Al Sb melt from the GaAs substrate. This effect is supposed to be due to the change in phase equilibria conditions caused by large lattice mismatch between the substrate and the solid in equilibrium with the liquid.     

Mass transfer during growth of Ga?In?P?As solid solution in the equilibrium cooling growth technique

Kinetical analysis of crystallization of Ga In P As solid solutions grown by equilibrium cooling growth technique was performed. Theoretical data were compared with experimental data on LPE of the material. The dependencies of layer thickness, lattice mismatch variation between the substrate and layer and energy gap in the layers lattice matched to InP were calculated for different growth temperatures.     

Liquid Phase Epitaxy of SiC in the System Si?Tb?SiC by Temperature Gradient Zone Melting (I). Investigation of Solubilities in the System Si?Tb?SiC

In the paper which is divided into three parts the liquid phase epitaxy of SiC by temperature gradient zone melting with the solvent Si Tb is discussed. In the first part the solubility of SiC at different initial compositions of the Si Tb solvent is studied in the temperature range 2000–2500 K.     

X-ray powder diffraction investigations of solid solutions with limited miscibility in the KNO3?NH4NO3?H2O system at 298 K

The measurements of crystal lattice parameters (a, b, c) were conducted and the volumes (v) of unit cells of solid solutions forming in the system KNO₃ NH₄NO₃ H₂O at 298 K were calculated. It was established that in this system at 298 K two series of solid solutions were formed: the mNH₄NO₃ · n(KNO₃ · 2 NH₄NO₃) solid solution with the gap of miscibility and the kKNO₃ · l(KNO₃ · 2 NH₄NO₃) solid solution with one-sided limited miscibility.     

Preparation and phase characterization of the SrCl2?EuCl2 and SrCl2?EuCl3 systems

The SrCl₂ EuCl₂ and SrCl₂ EuCl₃ systems were investigated over the full composition ranges by the Guinier powder X-ray diffraction technique. In the strontium chlorideeuropium dichloride system the solubility from the both ends of reactants was found when fast cooling of the melt was used. In the strontium chloride-europium trichloride system a solid solution for the composition region up to 20 mol per cent of EuCl₃ and two new intermediate chlorides, Sr₄EuCl₁₁ and Sr₉Eu₅Cl₃₃, were observed. The compounds crystallize in orthorhombic symmetry with lattice parameters of 7.220(2), 35.15(1), 6.790(4) and hexagonal 12.854(4) and 24.702(8), respectively.     

Peculiarities in the X-ray Spectral Microanalysis of the Sn?Te?I System

This is an examination of the methodological specificities of the roentgenospectral microanalysis of the Sn Te I system, involving the application of a graphoanalytical method used in the analysis of ternary systems according to data calculated for the binary ones. The calculations were made on an ES 1060 computer in FORTRAN-4. The calculations are for different selection angles of the microanalyzer, and for a broad interval of values of the accelerating voltage. In this manner the method offered is applicable to any type of microanalyzer, and not only to the Cameca MS-46 used by us.     

Preparation of Al?Ga?P?As heterostructures

The present paper reports on the results of an investigation of crystallization of multilayer structures with a narrow-gap semiconductor surrounded by two wide-gap ones in the Al-Ga-P-As system on GaAs and GaP substrates. Influence of the lattice parameters' difference on the value of thermal stress in structures with a composition gradient was determined by the bend of structures separated from the substrate. It has been proved that with the P concentration in solid solutions being less than 1% heterojunctions with less tensions than in the Al–Ga–As system are available. A new method of obtaining Al_xGa_1–xP_yAs_1–y solid solutions with the concentration of P proportional to that of Al has been worked out on the basis of which multilayer heterolight-emitting structures have been prepared.     

Effect of structural transformations on the texture of Ni?Fe base alloys

1. Processes of texture formation were studied in three Ni Fe system alloys containing Mo and Ti (alloy No. 1), Cr, Ti and Al (alloy No. 2) and Co, Ti and Al (alloy No. 3). The deformation texture is identical in all alloys which agrees with the proximity of stacking fault energies as estimated from X-ray data. 2. Annealing leads to a pronounced diffusion and alteration of the texture in alloy No. 1, but does not alter the texture type and intensity in alloy No. 2, whereas in alloy No. 3 the typical strain texture components are intensified. 3. Structure processes governing texture formation were identified as recrystallization in alloy No. 1, and oriented γ–γ′ transformation in alloys No. 2 and 3 where the intergranular boundaries were blocked by heterogenous precipitation of phases not possessing fcc structure.     

Glass formation and properties of chalcogenide systems (XXII) the phase diagram of the system PbSe?GeSe2 and on the compound Pb2GeSe4

The phase diagram of the system PbSe GeSe₂ is studied by X-ray analysis and DTA. Pb₂GeSe₄ is the only compound which is formed in the system. It melts incongruently at 590 ± 4°C. The formation of Pb₂GeSe₄ as a definite compound is supported by studying the phase relations in the corresponding area of the ternary system PbSe GeSe GeSe₂.