Extended Data Fig. 4: Modified iron sulfide grain including pentlandite, pyrrhotite (Fe1- xS) and troilite (FeS). | Nature Astronomy

Extended Data Fig. 4: Modified iron sulfide grain including pentlandite, pyrrhotite (Fe1- xS) and troilite (FeS).

From: Influx of nitrogen-rich material from the outer Solar System indicated by iron nitride in Ryugu samples

Extended Data Fig. 4

a. BF-TEM image of the iron sulfide. The grain surface is protected by a platinum coat (Pt-C). b-c. Selected area electron diffraction patterns of the iron sulfides obtained from circled areas in (a). Diffraction pattern near the grain surface (b) is dominated by troilite, while that from the inner region (c) consists of equal amount of troilite and non- integral (NC) pyrrhotite. Both patterns are indexed based on the NiAs-type subcell (superscript N) and troilite (superscript T). Black and gray arrows denote superstructures of troilite and pyrrhotite, respectively. d. HAADF-STEM image of the modified sulfide grain. e-f. STEM-EDS elemental maps of the modified iron sulfide. Composite color map in (e) consists of sulfur (red), iron (green), and nickel (blue). Arrows in (e) show pentlandite lamellae. Composite color map in (f) consists of oxygen (red), silicon (green), and magnesium (blue). Arrows in (e) show silicon and magnesium-rich layer that is possibly vapor-deposited materials. g. BF-STEM image near the surface of the modified sulfide grain shown in (a) constructed from a STEM- NBD dataset. (h-j.) Position averaged NBD patterns of pentlandite at grain surface (h) and those obtained from interior of the iron.

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