The Influence of Crystal Defects on the Magnetic Behavior of Magnetite

小行星9304520 该提案的一个主要目标是研究晶体缺陷对磁铁矿和钛磁铁矿磁性行为的影响。 晶体缺陷可以作为新畴壁成核的中心并有助于磁化的变化，或者它们可以钉扎现有的畴壁并抑制磁化的变化。 除了一些基本的细节，有一个关于壁缺陷相互作用的定量知识缺乏。 具体地说，缺陷结构将被改变和操纵在一个受控的方式，通过体塑性变形，通过单颗粒微压痕，并通过热退火实验。 这些实验的主要目的将是确定矫顽力和剩磁如何随变形程度和通过退火的恢复而变化，并对最近的理论微磁模型进行严格评估，以确定特定类型和安排的缺陷所产生的矫顽力的热依赖性。 ***

9304520 Moskowitz A major goal of this proposal is to study the influence of crystal defects on magnetic behavior in magnetite and titanomagnetite. Crystal defects can act as centers for the nucleation of new domain walls and aid changes in magnetization, or they can pin existing domain walls and inhibit changes in magnetization. Aside from some rudimentary details, there is a lack of quantitative knowledge about wall-defect interactions. Specifically, defect structures will be changed and manipulated in a controlled manner by bulk plastic deformation, by single grain micro-indentation, and by thermal annealing experiments. The main purpose of these experiments will be to determine how coercivity and remanence varies with the degree of deformation and with recovery through annealing and to assess critically recent theoretical micromagnetic models for the thermal dependence of coercivity produced by specific types and arrangements of defects. ***