硼化鋨
硼化鋨是鋨和硼的化合物。它們最顯著的特性是潛在的高硬度。人們認為鋨的高電子密度和硼-鋨共價鍵的強度會使鋨硼化物成為超硬材料,但這仍未得到證實。例如,OsB2很堅硬(硬度與藍寶石相若),但不足以稱得上超硬材料。[1]
合成
硼化鋨在真空或惰性環境中製備,以防止危險的四氧化鋨形成。硼化鋨在高溫(~1000 °C)下由MgB2和OsCl3的混合物合成。[1]
結構
已知至少有三種硼化鋨:OsB、Os2B3和OsB2。前兩者具有六邊形結構,[2]類似於二硼化錸。二硼化鋨最初也被認為具有六方的,[3]但它的一個相後來被重新分配為正交相。[1][4]在近期合成方法中,發現Os2的六方相具有與ReB2相似的結構。[5]
參考文獻
- ^ 1.0 1.1 1.2 Cumberland, Robert W.; et al. Osmium Diboride, An Ultra-Incompressible, Hard Material. Journal of the American Chemical Society. April 27, 2005, 127 (20): 7264–5. PMID 15898746. doi:10.1021/ja043806y.
- ^ M. Hebbache; et al. A new superhard material: Osmium diboride OsB2. Solid State Communications. 2006, 139 (5): 227–231. Bibcode:2006SSCom.139..227H. doi:10.1016/j.ssc.2006.05.041.
- ^ Kempter, C. P.; Fries, R. J. Crystallography of the Ru-B and Os-B Systems. The Journal of Chemical Physics. 1961, 34 (6): 1994. Bibcode:1961JChPh..34.1994K. doi:10.1063/1.1731807.
- ^ Roof, R. B.; Kempter, C. P. New Orthorhombic Phase in the Ru-B and Os-B Systems. The Journal of Chemical Physics. 1962, 37 (7): 1473. Bibcode:1962JChPh..37.1473R. doi:10.1063/1.1733309.
- ^ Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E. Thermal stability of hexagonal OsB2. Journal of Solid State Chemistry. 2014-11-01, 219: 210–219. Bibcode:2014JSSCh.219..210X. doi:10.1016/j.jssc.2014.07.035.
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