当前位置: X-MOL 学术Phys. Chem. Miner. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
XAFS and XRD study on Fe, Ni, and Ge in iron meteorite NWA 859
Physics and Chemistry of Minerals ( IF 1.2 ) Pub Date : 2021-02-18 , DOI: 10.1007/s00269-021-01136-8
Huimin Shao , Hiroshi Isobe , Ginga Kitahara , Hiroshi Fukui , Akira Yoshiasa

Iron meteorites record the evolutionary and cosmochemical processes of their parent bodies. Fe–Ni phases in iron meteorites show complex textures from various thermal histories of parent bodies as well as the phase relationships and crystal chemistry of Fe–Ni metal. Synchrotron radiation-based X-ray absorption fine structure spectra and X-ray diffraction were applied herein to the study of iron meteorite NWA 859 Fe, Ni, and Ge contents at the K-edge, since they are effective techniques in identifying crystal structures in iron meteorites. The bond distances of Fe and Ni in tetrataenite and kamacite were detected. Field-emission scanning electron microscopy and energy-dispersive spectroscopy were used to observe the petrological and chemical characteristics of the main minerals, kamacite and tetrataenite, and the trace mineral schreibersite. The tetrataenite phase and body-centered cubic kamacite formed a Widmanstätten pattern and cloudy zone. The extended X-ray absorption fine structure (EXAFS) analyses of NWA 859 and a single-crystal diffraction of tetrataenite show that it has a near-face-centered cubic (FCC) tetragonal structure with 12 nearest-neighboring Ni, Fe, and Ge atoms at distances of rNi-(Ni, Fe) = 2.5170(13) Å, rFe-(Ni, Fe) = 2.534(3) Å, and rGe-(Ni, Fe) = 2.524(5) Å, respectively. Moreover, the X-ray absorption near-edge structure (XANES) spectra suggest that the Ge in tetrataenite exhibits a specific local structure with coordination number 12, suggesting that a new local structure of Ge-(Ni, Fe) was first discovered in extraterrestrial material, forming a stable tetragonal structure at approximately 688–618 K. X-ray absorption fine structure (XAFS) is an efficient technique that could provide us further information about local atomic structures and forming conditions in extraterrestrial materials without damage.



中文翻译:

XAFS和XRD研究陨石NWA 859中铁,镍和锗

铁陨石记录了其母体的进化和宇宙化学过程。铁陨石中的Fe-Ni相从母体的各种热史以及Fe-Ni金属的相关系和晶体化学来看,显示出复杂的织构。基于同步辐射的X射线吸收精细结构光谱和X射线衍射在这里用于研究K边缘铁陨石NWA 859 Fe,Ni和Ge的含量,因为它们是识别铁氧体晶体结构的有效技术。铁陨石。检测了四方体和kamacite中Fe和Ni的键距。利用场发射扫描电子显微镜和能量色散光谱法观察了主要矿物,黄铁矿和四方辉石以及痕量矿物白钨矿的岩石化学特征。四方体相和以体心为中心的立方高岭石形成了Widmanstätten模式和浑浊带。NWA 859的扩展X射线吸收精细结构(EXAFS)分析和四方晶石的单晶衍射表明,它具有近面心立方(FCC)四方晶结构,其中Ni,Fe和Ge相邻为12距离为r的原子Ni-(Ni,Fe)  = 2.5170(13)Å,r Fe-(Ni,Fe)  = 2.534(3)Å,r Ge-(Ni,Fe)  = 2.524(5)Å。此外,X射线吸收近边缘结构(XANES)光谱表明,四方晶石中的Ge表现出特定的局部结构,其配位数为12,这表明在地外星系中首次发现了新的Ge-(Ni,Fe)局部结构。 X射线吸收精细结构(XAFS)是一种有效的技术,可以为我们提供有关外地材料中局部原子结构和形成条件的进一步信息,而不会造成损坏。

更新日期:2021-02-18
down
wechat
bug