Ultra-incompressible Orthorhombic Phase of Osmium Tetraboride (OsB4) Predicted from First Principles

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• 作者：Meiguang Zhang ; Haiyan Yan ; Gangtai Zhang ; Hui Wang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：February 16, 2012
• 年：2012
• 卷：116
• 期：6
• 页码：4293-4297
• 全文大小：289K
• 年卷期：v.116,no.6(February 16, 2012)
• ISSN：1932-7455

文摘

Using the ab initio particle swarm optimization algorithm for crystal structure prediction, we have predicted an orthorhombic Pmmn structure for OsB₄, which is energetically much superior to the previously proposed WB₄-type structure. The Pmmn structure consists of irregular OsB₁₀ dodecahedrons connected by edges and is stable against decompression into a mixture of Os and B at ambient pressure. OsB₄ within this orthorhombic phase is found to be an ultra-incompressible and hard material due to its high bulk modulus (294 GPa) and large hardness (28 GPa), originating from the strong and directional covalent B鈥揃 and B鈥揙s bonds.