Ni_(100-x)P_x合金的X射线谱学研究

利用X射线吸收精细结构(XAFS)和X射线衍射(XRD)研究了化学还原法制备的不同磷含量的Ni_(100-x)P_x合金的原子和电子结构.结果表明,当x=10时,磷元素的掺入导致了NiP样品中fcc结构的镍晶格扭曲和膨胀,Ni-Ni第一近邻配位的键长约增加0.03 A.随着磷含量的增加,膨胀和扭曲加剧,当x达到14左右时,样品的fcc-Ni晶格被完全破坏,从而形成非晶态NiP合金.X射线吸收近边结构(XANES)的结果表明,低磷含量(x≤10)时NiP样品的电子结构没有明显的变化,随着磷含量的增加,Ni4p态的分布变得宽化和越来越弥散.而当x达到26时,有大量电荷从Ni原子转移到P原子.

X-Ray spectroscopy studies on Ni_(100-x)P_x alloys

X-ray absorption fine structure (XAFS) and X-ray diffraction (XRD) were utilized to investigate the atomic and electronic structures of Ni_(100-x)P_x alloys with different P contents prepared by chemical reduction method. The results show that as x=10, the doped P element leads to expansion and distortion of the Ni fcc lattice of fcc-NiP sample, the R_(Ni-Ni) increases by about 0.03 A. with the P content increasing, the expansion and distortion are strengthened. It is found that when x increases to a critical value of 14, the lattice of fcc-Ni is completely destroyed, and the amorphous NiP alloy is formed. The X-ray absorption near edge structure (XANES) results indicate that at a low concentration (x<10), no significant change in the electronic structure is observed. However, as P content increases, the distribution of the Ni 4p states becomes more diffuse and broader. When x=26, the white line feature of Ni K-edge implies that a large number of charges are transferred from Ni atoms to P atoms.