Wednesday, July 07, 2010

Fluorine Could Energize #FuelCells, #Superconductors

Some elements are known to have amazing semiconducting capabilities, but only under extreme pressures--such as fluorine, which researchers say can become both a semi- and super-condutor. Look for extreme-condition semiconductors using other unlikely elements as materials science matures over the rest of the decade. R.C.J.

Researchers working with funds from the Pentagon's Threat Reduction Agency and the National Science Foundation have demonstrated that fluorine can be compressed into both a semiconductor and crystalline metal. Applications could range from an ultra-powerful oxidizer for destroying toxic microbes to super-efficient fuel cells to room-temperature superconductors. By inserting xenon di-fluoride (XeF2, a material used to etch silicon) between two diamond anvils and applying almost half-a-million atmospheres (50 GPa), the researchers produced a two-dimensional graphite-like semiconductor. The application of almost 1 million atmospheres (100 Gpa) yielded crystalline metal. In this state, the highly concentrated fluorine could kill toxic microbes in seconds. Moreover, the energy used to compress it could be recovered as electricity from a modified fuel-cell. The researchers said their next step will be to synthesize the materials on a larger scale and find ways to stabilize them under ambient conditions. Applications also could include superconducting materials.
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