Acquisition of high-temperature rock-magnetic instruments

该项目将通过购买两台新仪器来扩大岩石磁性研究所(IRM)的实验能力：第一台是庇护研究MFP-3D磁力显微镜。该仪器绘制了磁性材料样品表面上方受控高度的磁场梯度的空间分布，分辨率为几十纳米，最大可达~100微米，从而可以观察材料的微磁结构(磁区和磁区壁)。除了室温成像，MFP-3D还允许高达400°C的高温成像，这是通过位于MFP-3D XY扫描平台上的单独高温环境平台(PolyHeater)实现的。加热和冷却可以在空气或受控气氛(例如，He、Ar、CO等)中进行。样品温度可保持优于0.2°C的精度，精度可达0.5°C，温度过冲小于0.2°C。所有控制和测量功能均可完全编程，可用于定制的加热-冷却成像实验。第二种是AGICO MFK1-FA卡普布里奇和CS4加热炉。这台仪器能同时测量两者？真的吗？(同相)和？想象的？(正交)复磁化率分量，具有三个交流工作频率(976、3904和15616赫兹)，施加的交流磁场强度范围从2 A/m到最大700A/m(取决于频率)。外加磁场和仪器响应功能的高度空间一致性使得可以精确测量各种大小和形状的地质样品的磁各向异性，MFK1-FA中集成的样品旋转器可以快速自动采集与方向相关的数据。CS4电炉与MFK1-FA集成，将能够在高温下测量频率和幅度相关的磁化率，这将是重要的新功能。这两台仪器的新高温能力将使岩石磁性研究所的常驻和访问研究人员能够探索磁记忆？的基本物理起源。在具有重要地质意义的磁性物质中，如磁铁矿、钛磁铁矿、赤铁矿、赤铁矿和磁黄铁矿。这些矿物微米到毫米大小的颗粒中的不均匀磁化作用为我们提供了古地磁记录？过去的地磁场强度和方向使我们能够研究地球的演化？S深部、构造板块运动，以及地球科学、生物科学、行星地质和陨石研究中的其他重大问题。观察矿物颗粒内的微磁结构及其随实验外加磁场和控制温度的变化，使我们能够研究自然磁记录的机制，了解它们对地质时代热或化学叠加的敏感性，并设计出从自然记录介质中恢复古地磁场数据的优化实验室方法。

The project will expand experimental capabilities at the Institute for Rock Magnetism (IRM) through the acquisition of two new instruments:The first is a Asylum Research MFP-3D Magnetic Force Microscope. This instrument maps the spatial distribution of magnetic field gradients at a controlled height above the surface of a magnetic material sample, with a resolution of a few tens of nanometers, over areas up to ~100 micrometers, thereby allowing observation of the micromagnetic structure of the material (domains and domain walls). In addition to room-temperature imaging, the MFP-3D also allows high-temperature imaging up to 400°C. This is accomplished with a separate high temperature environmental stage (PolyHeater) that sits on the MFP-3D XY scanning stage. Heating and cooling can be done in air or controlled atmospheres (e.g., He, Ar, CO, etc). Sample temperature can be maintained to better than 0.2°C precision with accuracy to 0.5°C and temperature overshoots less than 0.2°C. All control and measurement functions are fully programmable for custom heating-cooling imaging experiments. The second is an AGICO MFK1-FA Kappabridge and CS4 Furnace. This instrument measures both ?real? (in-phase) and ?imaginary? (quadrature) components of complex susceptibility, with three AC operating frequencies (976, 3904 and 15616 Hz) and a range of applied AC field intensities from 2 A/m up to a maximum of 700 A/m (depending on frequency). High spatial uniformity of both applied fields and the instrument response function allow accurate measurement of the magnetic anisotropy of geological samples having various sizes and shapes, and an integrated specimen rotator in the MFK1-FA enables rapid automated acquisition of orientation-dependent data. The CS4 furnace, integrated with the MFK1-FA, will enable measurements of frequency- and amplitude-dependent susceptibility at elevated temperature, which will be important new capabilities. The new high-temperature capabilities of these two instruments will allow resident and visiting researchers at the Institute for Rock Magnetism to probe the fundamental physical origins of magnetic ?memory? in geologically significant magnetic materials such as magnetite, titanomagnetite, hematite, hemoilmenite, and pyrrhotite. The nonuniform magnetizations in micrometer-to-millimeter sized particles of these minerals provide us with the paleomagnetic ?recordings? of past geomagnetic field strength and orientation that allow us to study the evolution of the earth?s deep interior, the motion of tectonic plates, and other significant problems in the geosciences, biosciences, planetary geology, and meteoritic studies. Observation of the micromagnetic configurations within mineral grains, and their changes with experimentally applied fields and controlled temperatures, allows us to study the mechanisms of natural magnetic recording, to understand their sensitivity to thermal or chemical overprinting over geologic time, and to devise optimized laboratory methods for the recovery of paleomagnetic field data from natural recording media.