Direct metallographic analysis of an iron meteorite using hard x-ray photoelectron emission microscopy

The local structure of an iron meteorite was analyzed using photoemission electron microscopy (PEEM) and hard x-rays. The x-ray absorption fine-structure spectrum was obtained for each pixel in the PEEM image. The spectrum provides a wide variety of information, e.g., chemical composition, electronic structure, and lattice structure, in the interface region of the Widmanstätten structure. The shape of the absorption edge and the radial distribution function indicate that the structural phase changes from body-to face-centered cubic phases as the Ni composition at the interface is increased. The use of PEEM and hard x-rays is an attractive approach for local structure analysis.