DOI: 10.1016/j.epsl.2019.116010
论文题名: Mind the gap: Towards a biogenic magnetite palaeoenvironmental proxy through an extensive finite-element micromagnetic simulation
作者: Berndt T.A. ; Chang L. ; Pei Z.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 532 语种: 英语
中文关键词: hysteresis
; magnetosome
; micromagnetic simulation
; palaeo-environment
; proxy
英文关键词: Coercive force
; Finite element method
; Hysteresis
; Magnetic logic devices
; Magnetite
; Morphology
; Saturation magnetization
; Coercivity of remanence
; magnetosome
; Magnetotactic Bacteria
; Micromagnetic modelling
; Micromagnetic simulations
; palaeo-environment
; proxy
; Saturation remanences
; Remanence
; finite element method
; hysteresis
; magnetic field
; magnetite
; magnetosphere
; magnetostratigraphy
; numerical model
; paleoenvironment
; paleomagnetism
英文摘要: Magnetotactic bacteria (MTB) preserved in sediments (magnetofossils) are highly sensitive to environmental and climatic forcing and can therefore be used as an easy-to-measure palaeo-environment proxy. It is known that magnetofossils occur with various morphologies – each with its own particular magnetic signature. We present the first systematic extensive micromagnetic study relating magnetosome chain morphology to their hysteresis parameters. We modelled more than 450 different intact magnetosome chains in the finite-element micromagnetic modelling software MERRILL, relating the morphology (magnetosome size, elongation, intra-chain spacing, and chain length) to the magnetic parameters of coercivity, coercivity of remanence, and saturation magnetization, and analyzing domain-states and switching modes. It is shown that magnetic properties are far dominated by the intra-chain spacing. However, analysis of a large set of published TEM images of different MTB strains shows a strong correlation between intra-chain spacing and grain size. This correlation can in principle be used to infer MTB morphology purely from magnetic measurements, providing a framework to use biogenic magnetite as a sensitive palaeo-environment proxy. Additionally, it is found that MTB carefully control intra-chain spacing during magnetosome synthesis to maximize saturation remanence as well as magnetic stability. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164863
Appears in Collections: 气候变化与战略
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作者单位: Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, 100871, China
Recommended Citation:
Berndt T.A.,Chang L.,Pei Z.. Mind the gap: Towards a biogenic magnetite palaeoenvironmental proxy through an extensive finite-element micromagnetic simulation[J]. Earth and Planetary Science Letters,2020-01-01,532