X-ray absorption fine structure(XAFS) spectroscopy has been widely used for decades in a wide range of scientific fields, including physics, chemistry, biology, materials sciences, environmental sciences, etc. This re...X-ray absorption fine structure(XAFS) spectroscopy has been widely used for decades in a wide range of scientific fields, including physics, chemistry, biology, materials sciences, environmental sciences, etc. This review article is devoted to the applications of XAFS in nanomaterials. The basic principles of XAFS are briefly described from the view point of practical application, including its theory, data analysis and experiments. Using selected examples from recent literatures, the power of XAFS in determination of local atomic/electronic structures is illustrated for various nanomaterials, covering metal and semiconductor nanoparticles, catalysts, core/shell structures, ultrathin nanosheets, and so on. The utilization of time-resolved XAFS technique is also briefly introduced, for in-situ probing the nucleation/growth processes of nanomaterials and identifying reaction intermediates of nanostructured catalysts under operando conditions.展开更多
利用荧光X射线吸收精细结构(X-ray absorption fine structure,XAFS)方法研究了分子束外延生长的自组装Ge/Si(001)量子点的扩散效应.原子力显微镜结果表明,在550℃的生长温度下形成了面密度为5.2×1011cm-2的高密度小尺寸量子点.XAF...利用荧光X射线吸收精细结构(X-ray absorption fine structure,XAFS)方法研究了分子束外延生长的自组装Ge/Si(001)量子点的扩散效应.原子力显微镜结果表明,在550℃的生长温度下形成了面密度为5.2×1011cm-2的高密度小尺寸量子点.XAFS结果表明,生长的Ge量子点样品覆盖Si层后在550℃温度退火,对Ge/Si之间的热扩散混合的影响较小.随着退火温度升高到800℃,Ge原子的第一近邻配位壳层中的Ge-Si配位的无序度由4.0×10-5nm2降低到2.9×10-5nm2,配位数由3.3升高到3.8,这表明Ge量子点样品中的Ge原子的近邻主要为Si配位原子,高温退火显著增加了Ge原子在Si层中的扩散.展开更多
基金supported by the National Natural Science Foundation of China (11135008, 11175184 and 11475176)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (11321503)
文摘X-ray absorption fine structure(XAFS) spectroscopy has been widely used for decades in a wide range of scientific fields, including physics, chemistry, biology, materials sciences, environmental sciences, etc. This review article is devoted to the applications of XAFS in nanomaterials. The basic principles of XAFS are briefly described from the view point of practical application, including its theory, data analysis and experiments. Using selected examples from recent literatures, the power of XAFS in determination of local atomic/electronic structures is illustrated for various nanomaterials, covering metal and semiconductor nanoparticles, catalysts, core/shell structures, ultrathin nanosheets, and so on. The utilization of time-resolved XAFS technique is also briefly introduced, for in-situ probing the nucleation/growth processes of nanomaterials and identifying reaction intermediates of nanostructured catalysts under operando conditions.
基金This work was supported by the National Natural Science Foundation of China(No.12075243)the National Key Research and Development Program of China(No.2017YFA0402800)。
文摘利用荧光X射线吸收精细结构(X-ray absorption fine structure,XAFS)方法研究了分子束外延生长的自组装Ge/Si(001)量子点的扩散效应.原子力显微镜结果表明,在550℃的生长温度下形成了面密度为5.2×1011cm-2的高密度小尺寸量子点.XAFS结果表明,生长的Ge量子点样品覆盖Si层后在550℃温度退火,对Ge/Si之间的热扩散混合的影响较小.随着退火温度升高到800℃,Ge原子的第一近邻配位壳层中的Ge-Si配位的无序度由4.0×10-5nm2降低到2.9×10-5nm2,配位数由3.3升高到3.8,这表明Ge量子点样品中的Ge原子的近邻主要为Si配位原子,高温退火显著增加了Ge原子在Si层中的扩散.
