Physics
Scientific paper
Dec 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007agufmgp24a..06k&link_type=abstract
American Geophysical Union, Fall Meeting 2007, abstract #GP24A-06
Physics
1519 Magnetic Mineralogy And Petrology, 1540 Rock And Mineral Magnetism, 1595 Planetary Magnetism: All Frequencies And Wavelengths, 6008 Composition (1060), 6030 Magnetic Fields And Magnetism
Scientific paper
Various FeNi phases are dominant magnetic phases in most chondritic meteorites. In addition, iron-bearing sulphides are present in meteorites and in cometary dust. The low-temperature magnetic properties of the daubreelite (FeCr2S4) and troilite (FeS) were investi-gated. Daubreelite is ferrimagnetic below its Curie temperature Tc = 150 - 170 K, depending on its exact chemical composition. On cooling through the Tc its saturation magnetization sharply increases up to a maximum of ~32 Am2/kg at 80 K, while the magnetic susceptibility ranges between 0.5-3.5 10 4 m3/kg reaching maximum immediately below Tc. Further cooling reveals a magnetic transition around 60 K (characterized by spin-glass-like features and cubic-to-triclinic symmetry reduction) manifesting itself in a local maximum of induced magnetization and susceptibility. Remanence acquired at 5 K shows a major drop at the transition. Troilite is antiferromagnetic at room temperature. At Tm = 62 +- 4 K we have found a magnetic transition which is likely due to spin canting. Below the transition both saturation magnetization and coercivity increase dramatically, the latter approaching 0.5 T at 5 K. Magnetic saturation is not reached in 5 T field at this temperature. However, susceptibility remains low (~4 10-7 m3/kg) with a local maximum at Tm (~1.7 10-6 m3/kg). Compared to FeNi, saturation magnetization of daubreelite at 10 K is lower by a factor of 7 and that of troilite is lower by a factor of about 200. Daubreelite can therefore contribute to or even control magnetic properties of bodies in the cold regions of Solar System. The low temperature magnetic signature of daubreelite is recognizable in magnetic measurements made on various enstatite chondrites and can thus be used to identify its presence.
Jackson Martin
Kletetschka Gunther
Kohout Tomas
Kosterov Andrei A.
Lehtinen Markku
No associations
LandOfFree
Low Temperature Magnetic Properties of Daubreelite, Troilite and Enstatite Chondrites does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Low Temperature Magnetic Properties of Daubreelite, Troilite and Enstatite Chondrites, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low Temperature Magnetic Properties of Daubreelite, Troilite and Enstatite Chondrites will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1410034