Observation of thermally-induced magnetic relaxation in a magnetite grain using off-axis electron holography
نویسندگان
چکیده
A synthetic basalt comprising magnetic Fe3O4 grains (~ 50 nm to ~ 500 nm in diameter) is investigated using a range of complementary nano-characterisation techniques. Off-axis electron holography combined with in situ heating allowed for the visualisation of the thermally-induced magnetic relaxation of an Fe3O4 grain (~ 300 nm) from an irregular domain state into a vortex state at 550 ̊C, just below its Curie temperature, with the magnetic intensity of the vortex increasing on cooling.
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Observing thermomagnetic stability of nonideal magnetite particles: Good paleomagnetic recorders?
The thermomagnetic behavior of remanence-induced magnetite (Fe3O4) particles in the pseudo-single-domain (PSD) size range (~0.1–10μm), which dominate the magnetic signature of many rock lithologies, is investigated using off-axis electron holography. Construction of magnetic induction maps allowed for the visualization of the vortex domain state in an individual Fe3O4 grain (~200 nm in diameter...
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