Development of high-resolution focussed ion beam-secondary ion mass spectrometry (FIB-SIMS) as a tool for Earth and Materials sciences

扫描电子显微镜(SEM)和聚焦离子束扫描电子显微镜(FIB-SEM)与能量色散光谱(EDS)和电子背散射衍射(EBSD)相结合，可以绘制数十到数百微米的面积的成分和晶体图谱，空间分辨率可能达到100 nm或更高。这里的问题是，EBSD和EDS对轻元素或同位素不敏感。在这个项目中，我们将开发一种新的分析层析方法，使用FIB和二次离子质谱仪(SIMS)相结合。这项层析成像技术将被集成到一个相关的方法中，使用光学显微镜、X射线层析成像、透射电子显微镜和原子探针层析成像。在这个项目中开发的显微技术将用于解决天然和合成样品中的各种复杂材料表征问题。这包括表征在西澳大利亚杰克山的锆石中发现的包裹体的微量元素和同位素组成。了解这些样品中发现的包裹体的矿物年龄，有可能解开古地磁学中的关键悬而未决的问题，例如地球磁场是从什么时候开始的？此外，页岩和砂岩的SIMS分析将用于了解与理解石油和天然气储集层行为相关的孔隙尺度上发生的溶解和再沉淀过程。这种相关的分析层析成像还将用于探索其他对能量存储重要的材料的化学行为，如固体氧化物电池。最后，这可以用来解决钢和核材料中沿晶界的轻元素偏析问题。FIB-SIMS实现的层析成像直接解决了分析长度-尺度和信息差距，这对于天然和合成材料的表征是重要的。本项目集中于探索SIMS层析-FIB-SEM和离子束显微镜的潜力，以开发一种质谱学技术，以解决ICPMS和APT之间的长度尺度信息差距。作为一种分析技术，SIMS提供的信息与传统的EDS分析方法有很大不同。值得注意的是，SIMS使以数十纳米的空间分辨率分析样品中的两种同位素痕量轻元素分布成为可能。此外，学生还将使用这种新的层析成像作为集成工作流程的一部分来设计和实施实验，从X射线和光学到透射电子显微镜或APT(毫米到原子)。学生将开发一种新的尖端分析层析成像技术，将使用离子束对样本进行顺序排序，然后将其与SIMS数据相结合，创建所研究体积的三维元素图。这项新技术将开启对样品中同位素和痕量/轻元素分布的三维探索。使用这项技术，学生将探索有关流体岩石相互作用的问题，以及与深层碳有关的问题。此外，与能量储存和回收有关的技术上重要的材料以及先进的冶金问题。

Scanning electron microscopy (SEM) and focused ion beam - scanning electron microscopy (FIB-SEM) combined with energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) allow for compositional and crystallographic mapping of tens to hundreds of microns of area, with potentially 100 nm spatial resolution or better. The problem here is that EBSD and EDS are not sensitive to light elements or isotopes. In this project we will develop a new analytical tomographic approach using the FIB combined with secondary ion mass spectroscopy (SIMS). This tomographic technique will be integrated into a correlative approach using optical microscopy, x-ray tomography, transmission electron microscopy and atom probe tomography.The microscopy techniques developed during this project will be used to address a variety of complex materials characterization problems in natural and synthetic samples. This includes characterizing the trace element and isotope compositions of inclusions found in zircons from the Jack Hills of Western Australia. Understanding the mineral ages of the inclusions found in these samples has the potential to unlock key outstanding questions in paleomagnetism, such as when did the Earth's magnetic field begin? Additionally, SIMS analysis of shale and sandstones will be used to understand dissolution and re-precipitation processes occurring at the pore scale relevant to understanding oil and gas reservoir behavior. This correlative analytical tomography will also be used to explore chemical behaviors in other materials important to energy storage, such as solid oxide batteries. Finally, this can be used to address light-element segregation along grain boundaries in steels and nuclear materials. FIB-SIMS enabled tomography directly addresses an analytical length-scale and information gap, which is important for the characterization of natural and synthetic materials.This project focuses on exploring the potential of SIMS tomography FIB-SEM and ion beam microscopes to develop a mass spectroscopic technique that addresses the length scale information gap between ICPMS and APT. SIMS as an analytical technique offers information significantly differ from that traditionally measured using EDS analysis. Significantly, SIMS makes it is possible to analyze both isotope trace light element distributions in a sample with a spatial resolution of tens of nanometers. Further, the student will also design and implement experiments using this new tomography as part of an integrated workflow, going from x-ray and optical down to TEM or APT (mm to atoms). Maintaining a data connection across length scales.The student will develop a new cutting edge analytical tomographic technique, combining the sequential sequencing of a sample using an ion beam and then combining it with SIMS data to create a three dimensional elemental map of the studied volume. This new technique will open up three-dimensional explorations into isotope and trace/ light element distributions through a sample. Using this technique the student will explore questions about fluid rock interactions and questions related to deep carbon. Further, technologically important materials related to the energy storage, and recovery as well as advanced metallurgical questions.