HR: 10:35h
AN: GP12A-02 INVITED     [Abstracts]
TI: Crystal Defects and Their Magnetic Effects: `Stories' From the Past and Present.
AU: * Banerjee, S K
EM: banerjee@umn.edu
AF: University of Minnesota-Twin Cities Department of Geology and Geophysics Institute for Rock Magnetism , 310 Pillsbury Drive SE 108 Pillsbury Hall, Minneapolis, MN 55455 United States
AB: Rock and mineral magnetists often ascribe unexpected magnetic behavior in minerals to crystal defects, when observable impurities and/or particle size variations cannot easily explain the anomalous results. However, pursuing a testable hypothesis regarding such defects can illuminate some cases leading to a more precise definition of such `defects' or the discovery that the observed behavior is not so `abnormal' after all. Hiding among David Dunlop's prodigious and well-known output on domain states and remanence behavior, there is also important research on mineral magnetism and mineral defects that have helped us understand the true nature of the weak magnetism of hematite and goethite, common magnetic minerals on the earth's surface. After highlighting Dunlop and his colleagues' contributions, I will update us regarding some very recent models that help us define the precise role of crystalline defects in influencing the magnetism of hematite and goethite.
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1519 Magnetic mineralogy and petrology
DE: 1540 Rock and mineral magnetism
DE: 3620 Mineral and crystal chemistry (1042)
DE: 3904 Defects
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005