Lancaster EPrints

Magnetic properties of some synthetic sub-micron magnetites.

Maher, Barbara A. (1988) Magnetic properties of some synthetic sub-micron magnetites. Geophysical Journal Royal Astronomical Society, 94 (1). pp. 83-96. ISSN 0956-540X

Full text not available from this repository.

Abstract

The grain size dependence of various mineral (rock) magnetic parameters has been determined, using a series of essentially pure, fine-grained (single domain, SD) and ultrafine-grained (superparamagnetic, SP) magnetites. The parameters measured include low-field susceptibility, frequency-dependent susceptibility, saturation remanence (SIRM), anhysteretic susceptibility (XARM), and coercivity of remanence ((B0)CR). The magnetites were produced in experiments designed to simulate possible pedogenic and biogenic pathways of magnetite formation. Their mean grain sizes range from 0.012 um to 0.06 um, and hence span the SP/SD boundary. Isothermal magnetic measurements were performed on two separate subsets of differing packing densities. The response of the magnetic parameters is modified by interaction effects, but they display continuous variation across the entire grain size range, confirming their value for rapid magnetic granulometry. Within the fine and ultrafine end of the magnetite grain size spectrum, susceptibility, frequency dependent susceptibility and XARM are notably responsive to grain size change. In terms of magnetic response (and also possibly of grain size, shape and absence of cation substitution), these synhtetic magnetites represent close analogues of those found in some soils and sediments.

Item Type: Article
Journal or Publication Title: Geophysical Journal Royal Astronomical Society
Uncontrolled Keywords: magnetite ; environmental magnetism ; magnetic granulometry ; synthetic magnetites ; superparamagnetic ; single domain
Subjects: G Geography. Anthropology. Recreation > G Geography (General)
Departments: Faculty of Science and Technology > Lancaster Environment Centre
ID Code: 354
Deposited By: Professor Barbara A Maher
Deposited On: 19 Jan 2007
Refereed?: Yes
Published?: Published
Last Modified: 17 Sep 2013 08:22
Identification Number:
URI: http://eprints.lancs.ac.uk/id/eprint/354

Actions (login required)

View Item