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论文类型：期刊论文

发表时间：2012-03-01

发表刊物：MATERIALS RESEARCH BULLETIN

收录刊物：SCIE、EI

卷号：47

期号：3

页面范围：867-877

ISSN号：0025-5408

关键字：Intermetallic compounds; Nanostructures; Chemical synthesis; Electrochemical measurements; Electrochemical properties

摘要：Nanostructured nickel silicides have been prepared by reduction and silicification of high-surface-area nickel oxide (145 m(2) g(-1)) produced via precipitation. The prepared materials were characterized by nitrogen adsorption, X-ray diffraction, thermal analysis, FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, magnetic and electrochemical measurements. The nickel silicide formation involves the following sequence: NiO (cubic) -> Ni (cubic) -> Ni2Si (orthorhombic) -> NiSi (orthorhombic) -> NiSi2 (cubic), with particles growing from 13.7 to 21.3 nm. The nickel silicides are ferromagnetic at room temperature, and their saturation magnetization values change drastically with the increase of Si content. Nickel suicides have remarkably low electrical resistivity and noble metal-like properties because of a constriction of the Ni d band and an increase of the electronic density of states. The results suggest that such silicides are promising candidates as inexpensive yet functional materials for applications in electrochemistry as well as catalysis. (C) 2011 Elsevier Ltd. All rights reserved.