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Remanent magnetization and coercivity of rocks under hydrostatic pressure up to 1.4 GPa
Author(s) -
Demory F.,
Rochette P.,
Gattacceca J.,
Gabriel T.,
Bezaeva N. S.
Publication year - 2013
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 - 10.1002/grl.50763
Subject(s) - remanence , coercivity , magnetite , magnetometer , magnetization , materials science , hydrostatic pressure , geology , hydrostatic equilibrium , single domain , natural remanent magnetization , mineralogy , nuclear magnetic resonance , magnetic domain , condensed matter physics , magnetic field , metallurgy , thermodynamics , physics , quantum mechanics
We designed an Isothermal Remanent Magnetization (IRM) acquisition system based on permanent magnets and sized to accommodate an amagnetic hydrostatic pressure cell. This pressure cell fits in a superconducting rock magnetometer, allowing for the measurement of remanent magnetization of pressurized samples. With this system, we determined the coercivity of remanence (B cr ) at different hydrostatic pressures up to 1.4 GPa for rock and dispersed mineral samples with various magnetic mineralogy and domain state. IRM and B cr are nearly identical before compression and after decompression, indicating no permanent changes in the magnetic properties during pressure cycling. Hydrostatic pressure up to 1.4 GPa does not significantly increases IRM under pressure except for multidomain pyrrhotite and magnetite which show an increase of about 40%. Relative increase of B cr under pressure is mild, except for a near single domain titanomagnetite where B cr doubles.