Publications by authors named "Martin Bettge"

It is well known that Li-ion cells containing manganese oxide-based positive electrodes and graphite-based negative electrodes suffer accelerated capacity fade, which has been attributed to the deposition of dissolved manganese on the graphite electrodes during electrochemical cell cycling. However, the reasons for the accelerated capacity fade are still unclear. This stems, in part, from conflicting reports of the oxidation state of the manganese species in the negative electrode.

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It is a well-known fact that a sphere offers less surface area, and thus less surface energy, than any other arrangement of the same volume. From this perspective, all other shapes are metastable objects. In this paper, we present and discuss a manifestation of this metastability: the spontaneous alignment of free-standing amorphous nanowires towards, and ultimately parallel to, a flux of directional ion irradiation.

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Vertically aligned silicon oxide nanowires can be synthesized over a large area by a low-temperature, ion-enhanced, reactive vapour-liquid-solid (VLS) method. Synthesis of these randomly ordered arrays begins with a thin indium film deposited on a Si or SiO(2) surface. At the processing temperature of 190 degrees C, the indium film becomes a self-organized seed layer of molten droplets, receiving atomic silicon from a DC magnetron sputtering source rather than from the gaseous precursors used in conventional VLS growth.

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BACKGROUND: In this paper, a physical method to prepare copper-nickel alloy particles in the sub-micron range for possible self controlled magnetic hyperthermia treatment of cancer is described. It is reported that an increase in tumor temperature decreases the tumor resistance to chemo- and radiation therapies. Self controlled heating at the tumor site to avoid spot heating is managed by controlling the Curie temperature of the magnetic particles.

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