Origin of oxygen isotopically anomalous material in carbonaceous chondrite

利用同步辐射X射线衍射仪和透射电子显微镜对碳质球粒陨石Acfer094中的同位素异常物质(COS)的化学和微观结构进行了研究。SR-X射线衍射仪和透射电子显微镜观察表明，COS颗粒由磁铁矿、磁黄铁矿(少量的镍黄铁矿)组成，具有数十nm尺度的晶格结构。这种纳米级的相互生长结构可能表明组成矿物在形成时同时快速的晶体生长。

Chemistry and microstructure of the isotopically anomalous material (COS) in the carbonaceous chondrite Acfer 094 are studied using synchrotron-radiation X-ray diffraction (SR-XRD) and transmission electron microscopy (TEM). SR-XRD and TEM observations shows that COS grain consists of magnetite+pyrrhotite (+minor pentlandite) with a symplectitic texture in tens nm scale. Such a nano-metered inter-growth texture may suggest the simultaneous and rapid crystal growth of the constituent minerals at the time of formation.