LINK<\/strong><\/a><\/p>\n\n\n\n“A fragment of Mundrabilla IAB-ung iron meteorite was analyzed using optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), magnetization measurements, and M\u00f6ssbauer spectroscopy. The polished section of meteorite fragment characterization by optical microscopy and SEM shows the presence of the \u03b3-Fe(Ni, Co) phase lamellae, plessite structures and schreibersite inclusions in the \u03b1-Fe(Ni, Co) phase. EDS indicates variations in the Ni concentrations in the following ranges: (i) \u223c6.3\u20136.5\u2009atom% in the \u03b1-Fe(Ni, Co) phase and (ii) \u223c22 to \u223c45\u2009atom% in the \u03b3-Fe(Ni, Co) phase lamellae including the range of \u223c29\u201333\u2009atom% of Ni leading to the paramagnetic state of the \u03b3-Fe(Ni, Co) phase. Schreibersite inclusions contain \u223c23\u2009atom% of P, \u223c33\u2009atom% of Fe, \u223c43\u2009atom% of Ni, and \u223c0.7\u2009atom% of Co. Plessite structure contains the average Ni concentration of \u223c17\u2009atom% while detailed EDS analysis shows: (i) the lowest Ni concentrations of \u223c5 to \u223c8\u2009atom%, (ii) the intermediate Ni concentrations of \u223c9 to \u223c19\u2009atom%, and (iii) the highest Ni concentration up \u223c38\u2009atom% (some individual micro-grains demonstrate up to \u223c47 and \u223c59\u2009atom% of Ni) that may indicate the presence of the (i) \u03b1-Fe(Ni, Co), (ii) \u03b12-Fe(Ni, Co), and (iii) \u03b3-Fe(Ni, Co) phases. These may be a result of the \u03b3-phase decomposition with mechanism \u03b3\u2009\u2192\u2009\u03b1\u2009+\u2009\u03b12\u2009+\u2009\u03b3 that indicates a slow cooling rate for Mundrabilla IAB-ung iron meteorite. The presence of \u223c98.6\u2009wt% of the \u03b1-Fe(Ni, Co) phase and \u223c1.4\u2009wt% of the \u03b3-Fe(Ni, Co) phase is found by XRD while schreibersite is not detected. Magnetization measurements show the saturation magnetization moment of Mundrabilla IAB-ung of 188(2) emu\u2009g\u22121 indicating a low average Ni concentration in Fe-Ni-Co alloy. M\u00f6ssbauer spectrum of the bulk Mundrabilla powder demonstrates five magnetic sextets related to the ferromagnetic \u03b12-Fe(Ni, Co), \u03b1-Fe(Ni, Co), and \u03b3-Fe(Ni, Co) phases and one singlet associated with the paramagnetic \u03b3-Fe(Ni, Co) phase, however, there are no spectral components corresponding to schreibersite. Basing on relatively larger and smaller values of the magnetic hyperfine field, two magnetic sextets associated with \u03b3-Fe(Ni, Co) phase can be related to the disordered and more ordered \u03b3-phases. The iron fractions in the detected phases can be roughly estimated as follows: (i) \u223c17.6% in the \u03b12-Fe(Ni, Co) phase, (ii) \u223c68.5% in the \u03b1-Fe(Ni, Co) phase, (iii) \u223c11.5% in the disordered \u03b3-Fe(Ni, Co) phase, (iv) \u223c2.0% in the more ordered \u03b3-Fe(Ni, Co) phase, and (v) \u223c0.4% in the paramagnetic \u03b3-Fe(Ni, Co) phase.”<\/p>\n","protected":false},"excerpt":{"rendered":"
M. V. Goryunov, G. Varga, Z. Dankh\u00e1zi, A. V. Chukin, I. Felner, E. Kuzmann, V. I. Grokhovsky, Z. Homonnay, M. I. Oshtrakh MAPSVersion of Record online: 11 September 2023 LINK “A fragment of Mundrabilla IAB-ung…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[371,214],"tags":[1881,595,3478,593,2693],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34161"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=34161"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34161\/revisions"}],"predecessor-version":[{"id":34162,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34161\/revisions\/34162"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34161"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34161"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}