Open AccessComposition law of oblique anhysteretic remanent magnetization and its relation to the magnetostatic interaction
Author(s) -
Sato Masahiko,
Mochizuki Nobutatsu,
Watanabe Minako,
Tsunakawa Hideo
Publication year - 2017
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2016gc006671
Subject(s) - remanence , demagnetizing field , paleomagnetism , coercivity , magnetization , geology , natural remanent magnetization , field (mathematics) , single domain , oblique case , condensed matter physics , magnetic field , thermoremanent magnetization , vector field , physics , mineralogy , nuclear magnetic resonance , geometry , magnetic domain , geophysics , mathematics , mechanics , linguistics , philosophy , quantum mechanics , pure mathematics
The basic properties of oblique anhysteretic remanent magnetization (OARM) acquired in a weak and steady magnetic field with an arbitrary angle to the alternating field direction were studied. OARM and rock‐magnetic experiments were conducted on samples of basalt, granite, and sediment containing noninteracting single domain (SD), interacting SD, pseudo‐single‐domain, and multidomain low‐Ti titanomagnetites. The intensity of OARM ( M OARM ) systematically increased or decreased with increasing angle between alternating and steady field directions ( θ SF ), while the angle between alternating field and OARM directions ( θ OARM ) increased with increasing θ SF for all samples. During stepwise alternating field demagnetization, the OARM vector shows a single component parallel to the steady field direction for θ SF = 0° (ARM ǁ ) and 90° (ARM ⊥ ). The median destructive field of ARM ⊥ is larger than that of ARM ǁ . For intermediate angles ( θ SF = 30°, 45°, and 60°), the OARM vector did not parallel the applied steady field but gradually increased θ OARM with higher coercivity. These experiments indicate that the OARM vector is approximately given by the sum of two orthogonal magnetizations coinciding with ARM ǁ and ARM ⊥ , respectively. Thus, the OARM vector can be determined by acquisition efficiencies of ARM ǁ and ARM ⊥ in an individual sample. Based on these experiments and associated rock‐magnetic measurements, noninteracting SD samples show lower ARM ⊥ /ARM ǁ ratios, compared to other samples. This result suggests that OARM can be used as a useful tool to detect noninteracting SD particles in the paleomagnetic samples.