Record details

    Out-of-phase magnetic susceptibility of rocks and soils: a rapid tool for magnetic granulometry
    Chadima, Martin
    Hrouda, F.
    Ježek, J.
    Pokorný, J.
Publication type
    článek v odborném periodiku
Source title - serial
    Geophysical Journal International
    Roč. 194, č. 1
    s. 170-181
    Projekt: GAP210/10/2351, GA ČR3cav_un_auth*0263318
    Rozsah: 12 s. : E
Subject category
    environmental magnetism
    magnetic mineralogy and petrology
    rock and mineral magnetism
Abstract (in english)
   The magnetic susceptibility measured in alternating field can be resolved into a component that is in-phase with applied field and a component that is out-of-phase. While the former component is widely used for solving various geophysical, geological and environmental problems, the latter component is paid only minor attention. The theoretical relationship between the frequency-dependent in-phase susceptibility and the out-of-phase susceptibility is described by the π/2 law valid for materials in which the latter is due to presence of magnetic particles on transition between superparamagnetic and stable single-domain states possessing sufficiently wide distribution of relaxation times.
   To advantageously use the out-of-phase susceptibility, which is measured simultaneously with the in-phase susceptibility during one measuring process, in magnetic granulometry, new parameters, XON and XOD, are proposed approximately converting the out-of-phase susceptibility into the XFN and XFD parameters of the frequency-dependent susceptibility. The validity of the new parameters was tested through mathematical modelling and through investigating samples of various sediments. The correlations found seem to be acceptable from the practical point of view. In addition, simple test is proposed for checking that the out-of-phase susceptibility is solely due to the viscous phenomena and not due to electrical eddy currents or weak field hysteresis.
   As the out-of-phase susceptibility is measured automatically along the in-phasesusceptibility with some instruments and can be directly interpreted in magnetic granulometry terms, it is to recommend to be routinely investigated in solving various problems of environmental magnetism.
    AV ČR Brno, Geologický ústav
Contributor code
    AV ČR, GLÚ
Source format
Import date
    23. 10. 2014