Quantum Mechanically Guided Design of Transition Metal Alloyed RuO2 Nanorods
Quantum Mechanically Guided Design of Transition Metal Alloyed RuO2 Nanorods
复制标题
过渡金属合金化 RuO2 纳米棒的量子机械引导设计
DOI：
10.1021/cg1008297
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发表时间：
2010
影响因子：
3.8
通讯作者：
J. Schneider
中科院分区：
文献类型：
--
作者：
D. Music;F. Basse;J. Schneider
利用从头算方法，探讨了所有4d过渡金属作为RuO2(P42/mnm空间群，原型金红石)潜在合金化元素对相稳定性和Seebeck系数的影响。Nb的加入可以提高相稳定性和Seebeck系数。在此设计方案的基础上，采用组合反应溅射法合成了三元化合物。X-射线衍射数据表明，Nb被掺入金红石结构中，其溶解度极限在3-4原子%范围内。当Nb含量为≥的2.9个原子%时，观察到纳米棒的形成。所有样品均存在金红石配位，且随着Nb含量的增加，出现Nb2O5配位。这可以基于我们的从头算分子动力学模拟来理解。原子尺度上的表面粗化是由于两个相邻的NbO_6八面体的O-交联性引起的。因此，假设NbO_6八面体有助于实验观察到的纳米棒的形成是合理的。
Using ab initio calculations, we have probed the effect of all 4d transition metals as potential alloying elements for RuO 2 (space group P4 2 /mnm, prototype rutile) on the phase stability and Seebeck coefficient. Nb additions were identified to increase both the phase stability and the Seebeck coefficient. Based on this design proposal, the ternary compound was synthesized by combinatorial reactive sputtering. X-ray diffraction data suggest that Nb is incorporated in the rutile structure with the solubility limit in the range 3—4 atom %. Nanorod formation is observed at Nb contents ≥2.9 atom %. Rutile coordination is present in all specimen, while with increasing Nb content Nb 2 O 5 coordination appears. This may be understood based on our ab initio molecular dynamics simulations. Surface coarsening on the atomic scale occurs due to O cross-linking of two neighboring NbO 6 octahedra. Hence, it is reasonable to assume that NbO 6 octahedra contribute toward the experimentally observed formation of nanorods.