Effect of Phosphorus Content on Local Structures of NiP Amorphous Alloys
Effect of Phosphorus Content on Local Structures of NiP Amorphous Alloys
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DOI：
10.1063/1.2644556
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发表时间：
2007-02
期刊：
影响因子：
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通讯作者：
Jinxia Song;Zheng Wei;Z. Pan;Z. Xie;Shiqiang Wei
中科院分区：
文献类型：
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作者：
Jinxia Song;Zheng Wei;Z. Pan;Z. Xie;Shiqiang Wei
用XAFS技术研究了化学还原法制备的不同磷含量的NiP非晶态合金的原子结构和电子结构。由EXAFS得到的径向结构函数（RSF）发现，P含量小于10at.%的非晶合金中，仍然呈现对应于高配位壳层的强峰，就像结晶Ni一样。这表明具有fcc结构的富Ni相的显著存在，其未被P原子显著改性。由于P含量高达14原子%，只能观察到RSF中的第一个壳峰，较高的壳峰消失。因此，样品是完全无定形的。XANES结果表明，当P浓度高于26at.%时，电荷从Ni原子转移到P原子。对于低于20at.%的P浓度，相反，电荷从P原子转移到Ni原子，当P浓度为14 × 20 at.%时，Ni原子的3d电子密度达到最大值。
XAFS technique is used to determine the atomic and electronic structures of NiP amorphous alloys with different P concentrations prepared by chemical reduction method. From the radial structural function (RSF) obtained from EXAFS, it is found that the amorphous alloys with P content less than 10 at.% still present strong peaks corresponding to high coordination shells just like crystalline Ni. This indicates the prominent existence of Ni‐rich phase with the fcc‐structure, which is not remarkably modified by the P atoms. As the P content is as large as 14 at.%, only the first shell peak in the RSF can be observed and the higher shell peaks disappear. Therefore the sample is totally amorphous. The XANES results show that as the P concentration is above 26 at.%, charge transfers from Ni atoms to P atoms. For P concentration lower than 20at.%, on the contrary, charge transfers from P atoms to Ni atoms, and 3d electron density of Ni atoms reaches the maximum when P concentration is about 14∼20 at.%.