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Meteorites contain microstructures formed under extreme conditions and durations. In iron-nickel meteorites, the combination of high pressures and temperatures coupled with slow cooling over millions of years allows for the formation of tetrataenite, a chemically ordered Fe-Ni alloy with a L10 tetragonal structure. This structure arises from the nickel enriched regions formed between areas of Widmanstätten growth. As these embayments slowly cool, they initially form a rim of tetrataenite that transitions into a spinodal decomposition known as the cloudy zone (CZ). The CZ microstructure consists of tetrataenite islands and a Fe-rich matrix. Research efforts have focussed on understanding the paleomagnetic remanence of the CZ as a record of dynamo formation on planetesimal bodies in the early Solar System. More recently, these structures have been studied to understand the factors that influence the formation of the CZ; if synthesised appropriately, the high natural magnetic coercivity of this material would provide a sustainable, cost-effective alternative to rare-earth permanent magnets. Trace elements have been suggested to accelerate the formation of the CZ.

Here we show analysis of the Imilac meteorite (main group pallasite), conducted using several characterisation techniques. Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry (SEM-EDS) was used to provide micron-scale chemical data and select areas for further analysis. Electron Probe Micro Analysis (EPMA) was used to verify bulk and trace element variation across different phases. EPMA was also used to verify Atom Probe Tomography (APT) compositions; from this, CZ island and matrix chemistry were determined. APT also showed the location of trace elements within CZ structures; islands are enriched in cobalt and copper while the matrix is enriched in manganese and germanium.

We will discuss our goals for future analysis with Transmission Electron Microscopy-Electron Energy Loss Spectrometry (TEM-EELS) and Differential Phase Contrast (DPC), as well as the challenges faced in characterising these samples.

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