LOW-TEMPERATURE MAGNETIC PROPERTIES OF THE NEUSCHWANSTEIN EL6 METEORITE

Abstract

The low-temperature magnetic properties of the Neuschwanstein EL6 meteorite as well as of the daubreelite (FeCr2S4), troilite (FeS), and FeNi mineral phases were investigated. Low-temperature magnetic behavior of the Neuschwanstein meteorite appears to be controlled mostly by FeNi. However, two magnetic features at ~ 70 K (Tm) and 150 K (Tc), are due to a magnetic transition in and Curie temperature of ferrimagnetic daubreelite. The ~ 10 K variations in Tm and Tc among daubreelite in the Neuschwanstein meteorite, daubreelite from the Coahuila meteorite and synthetic daubreelite [Tsurkan, V., Baran, M., Szymczak, R., Szymczak, H., Tidecks, R., 2001a. Spin-glass like states in the ferrimagnet FeCr2S4. Physica B, 296, 301-305.] might be due to slightly different Fe/Cr stoichiometric ratios, the presence of impurities, or crystalline lattice defects. In the antiferromagnetic troilite a magnetic transition at Tm ~ 60 K was identified. Its nature seems to be most likely due to a change in the orientation and attendant canting of the antiparallel spins. However, this feature was not identified in the Neuschwanstein meteorite measurements because of low concentration and weak magnetization of the troilite phase compared to those of FeNi and daubreelite. Daubreelite with its Tc ~ 160 K might be a significant magnetic mineral in cold environment. Low-temperature magnetic data of daubreelite, troilite and FeNi presented here are useful for the interpretation of the low-temperature magnetic measurements of various extraterrestrial materials and for the identification of the presence of these phases. © 2007 Elsevier B.V. All rights reserved.