Micromagnetic simulations of first-order reversal curve (FORC) diagrams of framboidal greigite
Micromagnetic simulations of first-order reversal curve (FORC) diagrams of framboidal greigite
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DOI：
10.1093/gji/ggaa241
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发表时间：
2020-05
影响因子：
2.8
通讯作者：
Miguel A. Valdez-Grijalva;L. Nagy;A. Muxworthy;W. Williams;A. Roberts;D. Heslop
中科院分区：
文献类型：
--
作者：
Miguel A. Valdez-Grijalva;L. Nagy;A. Muxworthy;W. Williams;A. Roberts;D. Heslop
硼硅镁石是一种敏感的环境指示剂，在自然界中以静磁相互作用的框架体形式存在。到目前为止，只有孤立的非相互作用的硼镁石颗粒的磁响应已被建模微磁性。我们在这里提出的滞后和一阶反转曲线（FORC）模拟framboidal硫砷铁矿（Fe3S4），并比较结果孤立的颗粒相似的大小。我们表明，这些静磁相互作用显着改变的framboid FORC响应相比，孤立的粒子，这使得磁响应类似于更大的（多畴）晶粒。我们还表明，framboidal信号图在不同地区的FORC图，这有利于framboidal和孤立的粮食信号之间的差异。鉴于大的云英岩晶体很少观察到在显微镜研究的天然样品，我们建议，识别多域样FORC信号的样品中已知含有丰富的云英岩可以解释为framboidal云英岩的证据。
Greigite is a sensitive environmental indicator and occurs commonly in nature as magnetostatically interacting framboids. Until now only the magnetic response of isolated non-interacting greigite particles have been modelled micromagnetically. We present here hysteresis and first-order reversal curve (FORC) simulations for framboidal greigite (Fe3S4), and compare results to those for isolated particles of a similar size. We demonstrate that these magnetostatic interactions alter significantly the framboid FORC response compared to isolated particles, which makes the magnetic response similar to that of much larger (multidomain) grains. We also demonstrate that framboidal signals plot in different regions of a FORC diagram, which facilitates differentiation between framboidal and isolated grain signals. Given that large greigite crystals are rarely observed in microscopy studies of natural samples, we suggest that identification of multidomain-like FORC signals in samples known to contain abundant greigite could be interpreted as evidence for framboidal greigite.