Lattice parameter and melting behavior of the ternary B2-phase in the Co-Ga-Ni system

Summary Lattice parameter and DTA-measurements were performed in the range of the ternary B2-phase in the Co-Ga-Ni system which exhibits a continuous range of homogeneity. Lattice parameter values are reported for three ternary sections with constant ratios ofx _Co/x _Ni=0.33, 1.00, and 3.00 as well as for the two limiting binaries. Solidus and liquidus temperatures are given for 0x _Co/x _Ni3.00. The results of the DTA-measurements in the Ga-Ni binary system indicate a somewhat wider range of homogeneity on the gallium-rich side as compared with literature data.

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Gitterparameter und Schmelzverhalten der ternären B2-Phase im System Co-Ga-Ni

Zusammenfassung Im Bereich der ternären B2-Phase im System Co-Ga-Ni, welche einen durchgehenden Homogenitätsbereich aufweist, wurden Gitterparameter bestimmt und Differenz-Thermo-Analyse durchgeführt. Werte für den Gitterparameter werden sowohl für drei ternäre Schnitte mit konstanten Verhältnissenx _Co/x _Ni=0.33, 1.00 und 3.00 angegeben als auch für die zwei angrenzenden binären Systeme. Für 0x _Co/x _Ni3.00 werden auch Solidus- und Liquidustemperaturen angegeben. Die Ergebnisse der DTA-Messungen im binären System Ga-Ni weisen auf der galliumreichen Seite — verglichen mit Literaturdaten — auf einen etwas breiteren Homogenitätsbereich hin.

     

Schwinger scattering of thermal neutrons on tungsten single crystals enriched by the 186 isotope

The coherent amplitude of thermal neutron scattering on¹⁸⁶W may be very small due to the interference between potential and resonance scattering. Thus, such a sample is very suitable for an investigation of other additional mechanism of scattering, e.g. Schwinger interaction, with the amplitude of the order of 10^–14 cm.Dedicated to the 25th anniversary of the Joint Institute for Nuclear Research.The authors are indebted to Mr. J. Vávra and to Miss B. Haková for their valuable technical assistance.     

Integral enthalpy of mixing of the liquid ternary Au–Cu–Sn system

The integral enthalpy of mixing of the ternary Au–Cu–Sn has been determined with a Calvet type calorimeter at 6 different cross sections at 1273 K. The substitutional solution model of Redlich–Kister–Muggianu was used for a least square fit of the experimental data in order to get an analytical expression for the integral enthalpy of mixing. The ternary extrapolation models of Kohler, Muggianu and Toop were used to calculate the integral enthalpy of mixing and to compare measured and extrapolated values. Additional calculations of the integral enthalpy of mixing using the Chou model have been performed. With the calculated data, the iso-enthalpy lines have been determined using the Redlich–Kister–Muggianu model. A comparison of the data has been made.     

Preconcentration of Cd(II), Pb(II), Co(II), Ni(II), and Cu(II) by solid-phase extraction method using 1,10-phenanthroline

Solid-phase extraction (SPE) method for preconcentration and determination of Cd(II), Pb(II), Co(II), Ni(II), and Cu(II) aqueous samples by inductively coupled plasma optical emission spectrometry is described. The preconcentration of analytes is accomplished by retention of their chelates with 1.10-phenanthroline in aqueous solution on a solid phase containing carboxylic acid (COOH) bonded to silica gel in a column. The limits of detection values (defined as “3s” where “s” is standard deviation of the blank determination) are 3.6 μg/L for Cd(II), 17.5 μg/L for Pb(II), 3.1 μg/L for Co(II), 2.1 μg/L for Ni(II), and 4.4 μg/L for Cu(II) and corresponding limit of quantification (6s) values are 7.2, 35, 6.2, 4.2 and 8.8 μg/L, respectively. As a result, a simple method was elaborated for the group concentration and determination of the above mentioned metals in reference material and in samples of plant material. The article is published in the original.     

Strong biaxial texture and polymorph nature in TiO2 thin film formed by ex-situ annealing on c-plane Al2O3 surface

Many applications based on TiO₂ thin films are strongly influenced by the film crystalline quality, microstructure and surface morphology. We have utilized x-ray scattering methods for crystal structure study of TiO₂ films, grown by DC reactive magnetron sputtering without heating. We have observed the formation of ordered phases after post-deposition ex-situ annealing in air at 600 °C. The distinct biaxial texture with respect to the c-plane (0001) Al₂O₃ substrate surface, which developed during heating, shows remarkable patterns in pole figures. We have identified epitaxial relationships of anatase A(001)[110]6sub(001)[11?00] and rutile R(100)[001]6sub(0001)[100] within single TiO₂ layer. In addition, within the same sample, we have observed the anatase in (112) orientation with two in-plane relationship options A(112)[11?0]6sub(0001)[21?1?0] and A(112)[11?0]6sub(0001)[11?00].