Spontaneous Growth and Phase Transformation of Highly Conductive Nickel Germanide Nanowires

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• 作者：Chaoyi Yan ; Jeremy M. Higgins ; Matthew S. Faber ; Pooi See Lee ; Song Jin
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：June 28, 2011
• 年：2011
• 卷：5
• 期：6
• 页码：5006-5014
• 全文大小：1076K
• 年卷期：0
• ISSN：1936-086X

文摘

We report the synthesis, phase transformation, and electrical property measurement of single-crystal NiGe and ε-Ni<sub>5sub>Ge<sub>3sub> nanowires (NWs). NiGe NWs were spontaneously synthesized by chemical vapor deposition of GeH<sub>4sub> onto a porous Ni substrate without the use of intentional catalysts. The as-grown NWs of the orthorhombic NiGe phase were transformed to the hexagonal ε-Ni<sub>5sub>Ge<sub>3sub> phase by thermal annealing induced Ni enrichment. This controllable conversion of germanide phases is desirable for phase-dependent property study and applications, and the observation of novel metastable ε-Ni<sub>5sub>Ge<sub>3sub> phase suggests the importance of kinetic factors in such nanophase transformations. Electrical studies reveal that NiGe NWs are highly conductive, with an average resistivity of 35 ± 15 μΩ·cm, while the resistivity of ε-Ni<sub>5sub>Ge<sub>3sub> NWs is more than 4 times that of the NiGe phase. NWs of nickel germanides, particularly NiGe, would be useful building blocks for germanium-based nanoelectronic devices.