Low-temperature demagnetization isolates stable magnetic vector components in magnetite-bearing diabase
نویسندگان
چکیده
منابع مشابه
Ferromagnetic resonance and low-temperature magnetic tests for biogenic magnetite
Magnetite is both a common inorganic rock-forming mineral and a biogenic product formed by a diversity of organisms. Magnetotactic bacteria produce intracellular magnetites of high purity and crystallinity (magnetosomes) arranged in linear chains of crystals. Magnetosomes and their fossils (magnetofossils) have been identified using transmission electron microscopy (TEM) in sediments dating bac...
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The thermal demagnetization of pseudo-single-domain (PSD) magnetite (Fe3O4) particles, which govern the magnetic signal in many igneous rocks, is examined using off-axis electron holography. Visualization of a vortex structure held by an individual Fe3O4 particle (~250 nm in diameter) during in situ heating is achieved through the construction and examination of magnetic-induction maps. Stepwis...
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The room temperature co-precipitation of ferrous and ferric iron under alkaline conditions typically yields superparamagnetic magnetite nanoparticles below a size of 20 nm. We show that at pH = 9 this method can be tuned to grow larger particles with single stable domain magnetic (> 20-30 nm) or even multi-domain behavior (> 80 nm). The crystal growth kinetics resembles surprisingly observati...
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[1] Pelagic marine carbonates provide important records of past environmental change. We carried out detailed low-temperature magnetic measurements on biogenic magnetite-bearing sediments from the Southern Ocean (Ocean Drilling Program (ODP) Holes 738B, 738C, 689D, and 690C) and on samples containing whole magnetotactic bacteria cells. We document a range of low-temperature magnetic properties,...
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ژورنال
عنوان ژورنال: Geophysical Journal International
سال: 2004
ISSN: 0956-540X,1365-246X
DOI: 10.1111/j.1365-246x.2004.02201.x