Development of Mössbauer diffractometer by using nuclear resonant scattering at SPring-8 BL11XU
Development of Mössbauer diffractometer by using nuclear resonant scattering at SPring-8 BL11XU
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M的发展
DOI：
10.1007/s10751-016-1370-x
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发表时间：
2016
影响因子：
--
通讯作者：
Y. Kobayashi and S. Shimomura
中科院分区：
文献类型：
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作者：
S. Nakamura;T. Mitsui;K. Fujiwara;N. Ikeda;Y. Kobayashi and S. Shimomura
利用SPring-8 BL11XU上的57fe核共振散射装置研制了Mössbauer衍射仪，以获得晶体位置选择性Mössbauer光谱。在核单色仪和检测器之间新安装了一个𝜃-2𝜃goniometer。从安装在测角仪上的单晶fe3o4上，用111、222和220反射γ射线采集室温下的衍射光谱。A位和b位铁离子对应的两个子光谱的强度比随反射指数的变化而发生显著变化。衍射光谱由主要的吸收光谱和次要的发射光谱组成。前者由电子散射和核吸收引起的γ射线给出，后者由核共振散射引起的γ射线给出。这两种γ射线之间的干涉效应也被看作是线的加宽、不对称的线形和基线的斜率。这些特征可以用范诺函数成功地表示出来。我们认为由于核共振散射引起的发射光谱代表晶体位置选择性Mössbauer光谱。
A Mössbauer diffractometer has been developed by using57Fe nuclear resonant scattering apparatus at SPring-8 BL11XU in order to obtain a crystal-site-selective Mössbauer spectrum. A𝜃-2𝜃goniometer was newly installed between the nuclear monochromator and a detector. From a single crystal Fe3O4mounted on the goniometer, the 111, 222, and 220 reflectedγ-rays were used to collect the diffraction spectra at room temperature. The intensity ratio of the two subspectra, corresponding to A- and B-site Fe ions, changes notably according to the reflection index. The diffraction spectrum is composed of a major absorption spectrum and a minor emission spectrum. The former is given by theγ-ray due to the electron scattering and nuclear absorption, whereas the latter is given by theγ-ray due to the nuclear resonant scattering. Interference effects between these twoγ-rays are also seen as line broadenings, asymmetric line shapes, and slope of the base lines. These features can be successfully expressed by a Fano function. We consider that the emission spectrum due to the nuclear resonant scattering represents crystal-site-selective Mössbauer spectrum.