Open AccessRelationship between median destructive field and remanent coercive forces for dispersed natural magnetite, titanomagnetite and hematite
Author(s) -
Dankers Peter
Publication year - 1981
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1981.tb02676.x
Subject(s) - magnetite , hematite , coercivity , remanence , grain size , mineralogy , demagnetizing field , materials science , hysteresis , geology , natural remanent magnetization , magnetic field , condensed matter physics , composite material , metallurgy , magnetization , physics , quantum mechanics
Summary. Remanent acquisition curves, remanent hysteresis curves and alternating field demagnetization curves were determined for a number of artificial rock specimens containing well‐defined grain‐size fractions between 5 and 250 μm of natural magnetite, titanomagnetite and hematite. From these curves, the remanent acquisition coercive force H ' cr , the remanent coercive force H cr and the median destructive field of IRM H ½I were determined. Theoretically these parameters should be the same for an assembly of non‐interacting, homogeneously distributed, randomly oriented single‐domain grains. For a given hematite specimen H ' cr , H cr and H ½I have about the same value in spite of the strong grain‐size dependence of these parameters. For each specimen of magnetite and titanomagnetite the value of H ' cr is larger than H cr which again is larger than H ½I . However, the ratios H ' cr / H cr and H ½I / H cr appear to have a (different) constant value. An interesting relationship which appears to hold for dispersed magnetite, titanomagnetite or hematite grains between 5 and 250 μm, independently of grain‐size, quantity and packing density of the magnetic material, is: