Epsilon Carbide: A Low-Temperature Component of Interplanetary Dust Particles

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Science  23 Dec 1983:
Vol. 222, Issue 4630, pp. 1327-1329
DOI: 10.1126/science.222.4630.1327


Transmission electron microscope study of a chondritic interplanetary dust particle has revealed the presence of epsilon iron-nickel carbide, a low- temperature carbide previously encountered only in metallurgical studies. In these studies ∈-carbide was synthesized by carburization of iron or nickel grains in a stream of carbon monoxide or carbon monoxide plus hydrogen. Similar carburization of an iron-nickel metal in situ may have produced ∈-carbide during particle heating on atmospheric entry or in solar orbit. Alternatively, the ε-carbide may be a by-product of Fischer-Tropsch reactions in the solar nebula. Such reactions have been proposed as the mechanism of hydrocarbon formation in the early solar system.