Structure and Mechanical Properties of Al–Ca–Mn–Fe–Zr–Sc Eutectic Aluminum Alloy after Warm Equal Channel Angular Pressing

Russian Journal of Non-Ferrous Metals - Recently developed multicomponent eutectic alloys based on Al–Ca are promising for practical application, since they are characterized by low density...     

Structure of lithium ion-conducting polymer membranes based on Nafion plasticized with dimethylsulfoxide

The products of solvation of lithiated Nafion with dimethylsulfoxide (DMSO) have been studied by ATR IR spectroscopy in the frequency range of 50–4000 cm^–1 in a vacuum at room temperature. Degree of solvation n = DMSO/Li has been varied in a range of 1.5–18.4. Based on analysis of the dependence of the spectral parameters on the n value, it has been concluded that the test samples contain DMSO molecules of two types. The first type includes molecules coordinated to the lithium ion through the formation of the metal–oxygen bond, and the second is DMSO molecules associated by intermolecular bonds similar to those in the liquid DMSO phase. The structure of the salt depends on n: the changes are attributed to the reorientation of polymer chain units. The coordination number of lithium has been estimated at four. It has been shown that the IR data are consistent with the data on the conductivity of lithiated Nafion membranes as a function of DMSO content, according to which the simplest transport unit is the tetrasolvate [Li(DMSO)₄]⁺. At temperatures below 0°C, all the samples exhibit an abrupt change in conductivity, which is attributed to the freezing of DMSO in the membrane matrix.     

An indirectly heated metal oxide hot cathode with a 100-cm<Superscript>2</Superscript> area

Results of designing of a sectioned metal oxide hot cathode with indirect heating and a total emission coating area of 100 cm² are described. The design of the hot cathode enables control of the working surface temperature and allows one to change emission surface without replacing the whole hot cathode. The thermal test results are presented. The possibility is shown of applying the hot cathode in the uncharacteristic mode of gas discharge formation in medium vacuum conditions.     

Magnetic ordering in Cr<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Hg<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Se crystals grown by solid-state recrystallization

Cr _x Hg_{1 − x} crystals grown by solid-state recrystallization have been characterized by electron paramagnetic resonance spectroscopy, transport measurements, and X-ray microanalysis. The results demonstrate that the crystals contain rectangular HgCr₂Se₄ inclusions elongated along one of their axes and irregularly shaped Cr _x Hg_{1 − x} and CrHg inclusions. In the range 77–400 K, the electrical properties of samples cut from different parts of the crystals are typical of semiconductors with a strongly degenerate electron gas.