期刊
AMERICAN MINERALOGIST
卷 94, 期 8-9, 页码 1120-1129出版社
MINERALOGICAL SOC AMER
DOI: 10.2138/am.2009.3167
关键词
Magnetite; clay; smectite; TEM; electron holography; electron tomography; granulometry; magnetic properties
资金
- Natural Environment Research Council [NE/C518422/1, NE/D002036/1]
- Hungarian Science Fund [OTKA 48607]
- Natural Environment Research Council [NE/D002036/1] Funding Source: researchfish
- NERC [NE/D002036/1] Funding Source: UKRI
When suspended in solution, clay platelets coated with nanometer-scale magnetite particles behave as magnetorheologic fluids that are important to a variety of industrial applications. Such dual-phase assemblages are also similar to natural aggregates that record the direction and intensity of the Earth's magnetic field in lake and marine depositional environments. This study characterizes the mineralogical structure and magnetic behavior of montmorillonite platelets coated with aggregates of nanometer-scale magnetite crystals. The distribution of magnetite crystal sizes in three different clay-magnetite assemblages was directly measured using conventional transmission electron microscopy and agrees within error with estimates derived from magnetic hysteresis measurements. Magnetic hysteresis and low field susceptibility measurements combined with electron holography experiments indicate that all three samples behave superparamagnetically at room temperature, and show increasing levels of single domain behavior as the samples are cooled to liquid nitrogen temperatures. At such low temperatures, magnetostatic interactions are observed to partially stabilize otherwise superparamagnetic grains in flux closure structures.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据