在国内发展了硬X射线微束掠入射实验方法,并将此具有微米级高空间分辨率的方法应用于纳米厚度薄膜的微区分析。该实验方法对分析样品表面或薄膜在微小区域的不均匀组分、结构、厚度、粗糙度和表面元素化学价态等信息具有重要意义。基于...在国内发展了硬X射线微束掠入射实验方法,并将此具有微米级高空间分辨率的方法应用于纳米厚度薄膜的微区分析。该实验方法对分析样品表面或薄膜在微小区域的不均匀组分、结构、厚度、粗糙度和表面元素化学价态等信息具有重要意义。基于X射线全反射原理,以微聚焦实验站的高通量、能量可调的单色微束X射线为基础,通过集成运动控制、光强探测、衍射和荧光探测,设计了掠入射实验方法的控制和数据采集系统。此系统采用分布式控制结构,并基于Experimental Physics and Industrial Control System (EPICS)环境设计SPEC控制软件。通过建立SPEC和EPICS的访问通道,实现SPEC软件对EPICS平台上设备的控制和数据获取。在所设计的控制和数据采集系统中,运动控制系统控制多维样品台电机的运动,实现定位样品位置和调节掠入射角;光强探测系统则监测样品出射光强度,通过样品台运动控制和光强探测的联控,实现样品台的扫描定位控制;通过衍射和荧光探测系统获取不同入射深度下样品的衍射峰强度和荧光计数。此外,为准确控制掠入射角角度,必须确定样品平面与X射线平行的零角度位置,对此给出一种自动定位零角度的方法,编写了该方法的控制算法,设计了相应的控制软件。零角度自动化定位的扫描结果表明,实验系统微区分析的空间分辨率达到2.8 μm,零角度定位精度小于±0.01°。利用该系统在上海光源微聚焦实验站首次实现了具有自动化准确控制零角度的微束掠入射X射线衍射和荧光同步表征的实验方法,实验中被测样品为10 nm Au/Cr/Si薄膜材料, Si基底最上层为10 nm厚的Au薄膜,其间为一层很薄的Cr粘附层。在不同掠入射角下测量样品的衍射信号,获取不同入射深度下样品的衍射峰强度,并实现在同一掠入射角下,同步采集样品的荧光计数信号,从而确定了样品表层的相结构信息以及荧光信号强度与入射角关系,实现了对纳米厚度薄膜在微小区域的相结构和组分分析。此外,通过该技术能够选取荧光计数最大值对应的入射角度,有助于提高后续发展的低浓度样品掠入射X射线吸收近边结构实验方法的信噪比。展开更多
The hard X-ray micro-focusing beamline(BL15U1) of SSRF is dedicated to hard X-ray micro/nanospectrochemical analysis consisting of X-ray fluorescence(XRF), X-ray absorption spectroscopy(XAS) and X-ray diffraction(XRD)...The hard X-ray micro-focusing beamline(BL15U1) of SSRF is dedicated to hard X-ray micro/nanospectrochemical analysis consisting of X-ray fluorescence(XRF), X-ray absorption spectroscopy(XAS) and X-ray diffraction(XRD) techniques. It is one of the most versatile instruments in hard X-ray microscopy science. Since its commission in 2009, BL15U1 has allocated over 25000 h beamtime for users, and about 700 proposals have been executed. The beamline and the experimental end-station were upgraded for several times to facilitate the users' experimental needs and make it more convenient to operate. In this paper, we give a review on the beamline, describing its characteristics, recent technical developments, and a few examples of scientific progresses achieved in recent years on BL15U1.展开更多
Microstructure and oxidation behavior of modified Ni-16Mo-7Cr-4Fe alloys by yttrium microalloying were investigated by scanning electron microscopy, transmission electron microscopy, grazing incident Xray diffraction ...Microstructure and oxidation behavior of modified Ni-16Mo-7Cr-4Fe alloys by yttrium microalloying were investigated by scanning electron microscopy, transmission electron microscopy, grazing incident Xray diffraction and synchrotron radiation X-ray fluorescence. M6 C and Ni17Y2 phases were observed and the amount of Ni17Y2 increased with yttrium concentration. When the yttrium concentration increased to 0.43 wt.%,some Ni17Y2 chains and multi phase regions containing Ni17Y2, M6 C and γ phase appeared, which is harmful for the oxidation resistance. The alloy containing 0.05 wt.% yttrium showed the best oxidation resistance, which derives its oxidation resistance from the adequate concentration of yttrium in the solid-solution(γ phase), the formation of the protective layer of YCr O3 and chromia oxide and the strengthening effect of yttrium on oxide boundaries.展开更多
To investigate the corrosion products of Cr in molten FLi Na K salt(46.5 mol% Li F–11.5 mol% Na F–42mol% KF), the corrosion test of the pure metal Cr was performed in molten FLi Na K salt at 700?C for 200 h.The FLi ...To investigate the corrosion products of Cr in molten FLi Na K salt(46.5 mol% Li F–11.5 mol% Na F–42mol% KF), the corrosion test of the pure metal Cr was performed in molten FLi Na K salt at 700?C for 200 h.The FLi Na K salt after the corrosion test was thoroughly investigated by X-ray absorption near-edge structure spectroscopy, a transmission electron microscope, and X-ray diffraction. The results demonstrate that the predominant oxidation state of Cr in FLi Na K salt is Cr^(3+), and the main corrosion product in cooled FLi Na K salt is K_2NaCrF_6.展开更多
High-pressure phase transitions of cubic Y_2O_3 are investigated using in situ synchrotron x-ray diffraction in a diamond anvil cell up to 36.3 GPa. The pressure-induced phase transitions of cubic Y_2O_3, which displa...High-pressure phase transitions of cubic Y_2O_3 are investigated using in situ synchrotron x-ray diffraction in a diamond anvil cell up to 36.3 GPa. The pressure-induced phase transitions of cubic Y_2O_3, which display apparent inconsistencies in previous studies, are verified to be from a cubic phase to a monoclinic phase and further to a hexagonal phase at 11.7 and 21.6 GPa, respectively. The hexagonal Y_2O_3 displays noticeable anisotropic compressibility due to its layered structure and it is stable up to the highest pressure in the present study. A third-order Birch–Murnaghan fit based on the observed pressure-volume data yields zero pressure bulk moduli of180(3), 196(7) and 177(7) GPa for cubic, monoclinic and hexagonal phases, respectively.展开更多
文摘在国内发展了硬X射线微束掠入射实验方法,并将此具有微米级高空间分辨率的方法应用于纳米厚度薄膜的微区分析。该实验方法对分析样品表面或薄膜在微小区域的不均匀组分、结构、厚度、粗糙度和表面元素化学价态等信息具有重要意义。基于X射线全反射原理,以微聚焦实验站的高通量、能量可调的单色微束X射线为基础,通过集成运动控制、光强探测、衍射和荧光探测,设计了掠入射实验方法的控制和数据采集系统。此系统采用分布式控制结构,并基于Experimental Physics and Industrial Control System (EPICS)环境设计SPEC控制软件。通过建立SPEC和EPICS的访问通道,实现SPEC软件对EPICS平台上设备的控制和数据获取。在所设计的控制和数据采集系统中,运动控制系统控制多维样品台电机的运动,实现定位样品位置和调节掠入射角;光强探测系统则监测样品出射光强度,通过样品台运动控制和光强探测的联控,实现样品台的扫描定位控制;通过衍射和荧光探测系统获取不同入射深度下样品的衍射峰强度和荧光计数。此外,为准确控制掠入射角角度,必须确定样品平面与X射线平行的零角度位置,对此给出一种自动定位零角度的方法,编写了该方法的控制算法,设计了相应的控制软件。零角度自动化定位的扫描结果表明,实验系统微区分析的空间分辨率达到2.8 μm,零角度定位精度小于±0.01°。利用该系统在上海光源微聚焦实验站首次实现了具有自动化准确控制零角度的微束掠入射X射线衍射和荧光同步表征的实验方法,实验中被测样品为10 nm Au/Cr/Si薄膜材料, Si基底最上层为10 nm厚的Au薄膜,其间为一层很薄的Cr粘附层。在不同掠入射角下测量样品的衍射信号,获取不同入射深度下样品的衍射峰强度,并实现在同一掠入射角下,同步采集样品的荧光计数信号,从而确定了样品表层的相结构信息以及荧光信号强度与入射角关系,实现了对纳米厚度薄膜在微小区域的相结构和组分分析。此外,通过该技术能够选取荧光计数最大值对应的入射角度,有助于提高后续发展的低浓度样品掠入射X射线吸收近边结构实验方法的信噪比。
基金Supported by the National Natural Science Foundation of China(Nos.U1332117 and U1332120)Natural Science Foundation of Shanghai(No.14ZR1448200)
文摘The hard X-ray micro-focusing beamline(BL15U1) of SSRF is dedicated to hard X-ray micro/nanospectrochemical analysis consisting of X-ray fluorescence(XRF), X-ray absorption spectroscopy(XAS) and X-ray diffraction(XRD) techniques. It is one of the most versatile instruments in hard X-ray microscopy science. Since its commission in 2009, BL15U1 has allocated over 25000 h beamtime for users, and about 700 proposals have been executed. The beamline and the experimental end-station were upgraded for several times to facilitate the users' experimental needs and make it more convenient to operate. In this paper, we give a review on the beamline, describing its characteristics, recent technical developments, and a few examples of scientific progresses achieved in recent years on BL15U1.
基金Supported by the program of International S&T Cooperation(No.2014D FG60230)the National Natural Science Foundation of China(Nos.51371189 and 51371188)+1 种基金Science and Technology Commis sion of Shanghai Municipality(No.11JC1414900)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Microstructure and oxidation behavior of modified Ni-16Mo-7Cr-4Fe alloys by yttrium microalloying were investigated by scanning electron microscopy, transmission electron microscopy, grazing incident Xray diffraction and synchrotron radiation X-ray fluorescence. M6 C and Ni17Y2 phases were observed and the amount of Ni17Y2 increased with yttrium concentration. When the yttrium concentration increased to 0.43 wt.%,some Ni17Y2 chains and multi phase regions containing Ni17Y2, M6 C and γ phase appeared, which is harmful for the oxidation resistance. The alloy containing 0.05 wt.% yttrium showed the best oxidation resistance, which derives its oxidation resistance from the adequate concentration of yttrium in the solid-solution(γ phase), the formation of the protective layer of YCr O3 and chromia oxide and the strengthening effect of yttrium on oxide boundaries.
基金Supported by Science and Technology Commission of Shanghai Municipality(No.11JC1414900)National Basic Research Program of China(No.2010CB934501)+2 种基金the "Strategic Priority Research Program" of Chinese Academy of Sciences(No.XDA02040000)National Natural Science Foundation of China(Nos.11005148 and 51371188)the Special Presidential Foundation of Chinese Academy of Sciences,China(No.29)
文摘To investigate the corrosion products of Cr in molten FLi Na K salt(46.5 mol% Li F–11.5 mol% Na F–42mol% KF), the corrosion test of the pure metal Cr was performed in molten FLi Na K salt at 700?C for 200 h.The FLi Na K salt after the corrosion test was thoroughly investigated by X-ray absorption near-edge structure spectroscopy, a transmission electron microscope, and X-ray diffraction. The results demonstrate that the predominant oxidation state of Cr in FLi Na K salt is Cr^(3+), and the main corrosion product in cooled FLi Na K salt is K_2NaCrF_6.
基金the National Natural Science Foundation of China under Grant Nos 11775292,11104307 and U1530134the Natural Science Foundation of Shanghai under Grant No 18ZR1448100the Shanghai Sailing Program under Grant No 17YF1423600
文摘High-pressure phase transitions of cubic Y_2O_3 are investigated using in situ synchrotron x-ray diffraction in a diamond anvil cell up to 36.3 GPa. The pressure-induced phase transitions of cubic Y_2O_3, which display apparent inconsistencies in previous studies, are verified to be from a cubic phase to a monoclinic phase and further to a hexagonal phase at 11.7 and 21.6 GPa, respectively. The hexagonal Y_2O_3 displays noticeable anisotropic compressibility due to its layered structure and it is stable up to the highest pressure in the present study. A third-order Birch–Murnaghan fit based on the observed pressure-volume data yields zero pressure bulk moduli of180(3), 196(7) and 177(7) GPa for cubic, monoclinic and hexagonal phases, respectively.
