DOI: 10.1016/j.epsl.2017.12.015
Scopus记录号: 2-s2.0-85037810269
论文题名: The magnetic structure and palaeomagnetic recording fidelity of sub-micron greigite (Fe3S4)
作者: Valdez-Grijalva M.A. ; Nagy L. ; Muxworthy A.R. ; Williams W. ; Fabian K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 483 起始页码: 76
结束页码: 89
语种: 英语
英文关键词: greigite
; micromagnetics
; pseudo single-domain
Scopus关键词: Finite element method
; Geomagnetism
; Iron compounds
; Magnetization
; Magnetostatics
; Closure-domain
; Greigites
; Magnetostatic interactions
; Micromagnetic modeling
; Micromagnetics
; Nudged elastic band methods
; Pseudo single domains
; Superparamagnetics
; Magnetic domains
; grain size
; greigite
; magnetic property
; magnetization
; paleomagnetism
英文摘要: We present the results of a finite-element micromagnetic model of 30nm to 300nm greigite (Fe3S4) grains with a variety of equant morphologies. This grain size range covers the magnetic single-domain (SD) to pseudo single-domain (PSD) transition, and possibly also the PSD to multi-domain (MD) transition. The SD–PSD threshold d0 is determined to be 50nm≤d0≤56nm depending on grain shape. The nudged elastic-band method was used to determine the room temperature energy barriers between stable states and thus the blocking volumes. It is found that, in the absence of interparticle magnetostatic interactions, the magnetisation of equant SD greigite is not stable on a geological scale and only PSD grains ≥70nm can be expected to carry a stable magnetisation over billion-year timescales, i.e., all non-interacting SD particles are essentially superparamagnetic. We further identify a mechanism for the PSD to multi-domain (MD) transition, which is of a continuous nature from PSD nucleation up to 300nm, when structures typical of MD behaviour like closure domains begin to form. © 2017 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110089
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Earth Science and Engineering, Imperial College LondonSW7 2BP, United Kingdom; School of GeoSciences, University of EdinburghEH9 3FE, United Kingdom; Geological Survey of NorwayN-7491, Norway
Recommended Citation:
Valdez-Grijalva M.A.,Nagy L.,Muxworthy A.R.,et al. The magnetic structure and palaeomagnetic recording fidelity of sub-micron greigite (Fe3S4)[J]. Earth and Planetary Science Letters,2018-01-01,483