Origin of self-reversed thermoremanent magnetization

The ability of certain magnetic minerals to acquire a remanent magnetization that opposes the direction of the Earth's magnetic field has fascinated rock magnetists since its discovery in 1951. Here, we determine the origin of this phenomenon, which is termed self-reversed thermoremanent magnet...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2005-12, Vol.95 (26), p.268501.1-268501.4, Article 268501
Main Authors: HARRISON, Richard J, KASAMA, Takeshi, WHITE, Thomas A, SIMPSON, Edward T, DUNIN-BORKOWSKI, Rafal E
Format: Article
Language:English
Subjects:
Computer Simulation
Earth sciences
Earth, ocean, space
Exact sciences and technology
Geophysics: general, magnetic, electric and thermic methods and properties
Internal geophysics
Magnetics
Minerals - chemistry
Models, Chemical
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The ability of certain magnetic minerals to acquire a remanent magnetization that opposes the direction of the Earth's magnetic field has fascinated rock magnetists since its discovery in 1951. Here, we determine the origin of this phenomenon, which is termed self-reversed thermoremanent magnetization (SR-TRM). We present direct transmission electron microscopy observations of negative exchange coupling across antiphase domain boundaries (APBs) in ilmenite-hematite. This coupling is linked intrinsically to the origin of SR-TRM and is responsible for the formation of two new classes of magnetic domain wall at APBs. We present simulations of the chemical and magnetic structure of the APBs and show that SR-TRM is generated by coupling between strongly ferrimagnetic Ti-rich domains and weakly ferrimagnetic Fe-rich domains, which form during the transition from short- to long-range cation order.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.95.268501