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Low temperature magnetic transition of chromite in ordinary chondrites
Author(s) -
Gattacceca J.,
Rochette P.,
Lagroix F.,
Mathé P.E.,
Zanda B.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl047173
Subject(s) - meteorite , chondrite , chromite , ferrimagnetism , ordinary chondrite , troilite , magnetization , geology , magnetic mineralogy , paramagnetism , chemical composition , phase transition , maghemite , materials science , mineralogy , condensed matter physics , remanence , geochemistry , astrobiology , physics , thermodynamics , magnetic field , hematite , quantum mechanics
We present low temperature magnetic data (thermal demagnetization, hysteresis) obtained on thirty three ordinary chondrite meteorites. A magnetic transition is observed in the 40–80 K range (average 66 K), and is interpreted as a ferrimagnetic to paramagnetic phase transition. We present quantitative analyses of changes in magnetization across the magnetic phase transition and chemical elemental analyses to argue that chromite, a common accessory mineral in meteorites, is the mineral undergoing the phase transition, and not troilite or tetrataenite as proposed in previous studies. Moreover, we observe a correlation between the measured Curie temperature and chemical composition of chromites in ordinary chondrites. Low temperature magnetic measurement are thus a sensitive indicator of chromite composition in these meteorites, and as such a possible proxy to the understanding of their thermal metamorphism.