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Bezprądowe cynowanie miedzi z roztworów tiomocznikowych

Araźna A., Kozioł G., Gromek J., Bieliński J.

Przegląd Elektrotechniczny

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2014

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R. 90, nr 9

9-11

PL

W pracy dyskutowana jest zależność pomiędzy szybkością procesu immersyjnego cynowania i warunkami prowadzenia tego procesu, takimi jak stężenie kwasu i tiomocznika w roztworze do cynowania na bazie soli chlorkowej (SnHCl) lub soli metanosulfonianowej (SnMSA). Oceniana jest również lutowność warstw Sn. Wyniki eksperymentów wykazują znaczący wpływ stężenia tiomocznika i kwasu na szybkość procesu cynowania, niezależnie od typu roztworu do cynowania. Szybkość osadzania warstw Sn wzrastała ze wzrostem tiomocznika w roztworze. Natomiast szybkość cynowania początkowo rosła, a następnie malała ze wzrostem stężenia kwasu w roztworze. Lutowność badanych warstw bezpośrednio po ich wykonaniu była bardzo dobra lub dobra. Zwilżalność starzonych termicznie warstw cyny przez pastę lutowniczą była gorsza niż warstw w stanie dostawy i zależała od grubości warstw i typu roztworu, z którego były one osadzane. Różnica w lutowności warstw przypisywana była różnicy w ich strukturze i strukturze związków międzymetalicznych.

EN

In the presented work, the correlation between the immersion Sn coatings deposition rate and the deposition conditions, such as concentrations of acid and thiourea, from immersion tin plating solution based on hydrochloric (SnHCl) salt or methanesulphonic (SnMSA) salt, is discussed. The solderability of tin coatings is also tested. The experiment results show the significant influence of the thiourea and acid concentration on the Sn deposition rate irrespectively of the type of solution. The deposition rate increases with increased concentration of thiourea. However, the deposition rate first increased and then decreased with the increase in acid concentration. The solderability of as-deposited coatings was good or very good. The wettability of thermally aged tin coatings by the solder paste was worse than for as-deposited coatings and depended on the thickness and type of bath. It is being assigned to the difference in the structure of tin layers and intermetallic grains.

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Manufacture of calcium formate from sodium formate

Trybuła S. W., Terelak K. L.

Polish Journal of Chemical Technology

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2003

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Vol. 5, nr 3

17-18

EN

The concept of calcium formate process with the use of a double exchange reaction between sodium formate and calcium nitrate has been proposed. In order to choose the optimum technological version of that process, the preliminary research work was performed.

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Vibronic behaviour of octahedral Cu(II) complexes in Cu(2-benzoylpyridine)2(NO3)2x2H2O crystal with a weak superexchange coupling. Temperature EPR studies

Hoffmann S. K., Goslar J., Hilczer W., Goher M. A. S.

Bulletin of the Polish Academy of Sciences. Chemistry

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2000

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Vol. 48, No. 4

397-409

EN

Octahedral [Cu(2-benzoylpyridine)2 (H20)2] complexes in the Cu(2-Bzpy)2-(NO3)2 .2H2O are very dynamical and Cu(II) ions are very weakly coupled as it is shown by the single crystal EPR measurements in the temperature range 4.2-300 K. Rigid lattice limit (9 K) of spin-Hamiltonian parameters are: gx = 2.137, gy = 2.014, gz = 2.306 as determined by decoupling of exchange merged EPR lines. The ground state is predominantly Ix(2) -y(2)) with 8% of the Iz(2)) state. This mixing is produced by zero-point motions in the ground vibrational state and results in g x > gy with strong lowering of the gy-value. The decoupling procedure gave superexchange coupling parameter J = 0.0040 cm(1), which unexpectedly is temperature independent in contrast to other weakly coupled Cu(II) paramagnets. The g-factors show relatively strong temperature variations with gy practically not affected by temperature and a tendency to averaging of the g x and gz with room tem-perature parameters: g x = 2.161, gy = 2.013, gz = 2.285. This is explained as the pseudo Jahn-1eller effect with dynamical transitions between two elongated octahedral axes, i.e. O-Cu-O (x-axis) and H2O-Cu-H2O (z-axis) with N-Cu-N (y-axis) direction ill the in-plane coordination with pyridine nitrogen not affected by vibronic dynamics. The vibronic effect can be described by two-well model in the temperature range 80-150 K only with energy difference between the ground vibronic state in the well being 220 cm-l. At lower temperatures Cu(II) complexes are strongly localized in the deepest potential well, whereas at higher temperatures, the vibronic g-factor averaging is dominated by the other mechanism.