Nanoscopic Approaches in Earth and Planetary Sciences

The properties of matter at extreme length scales and the respective processes can differ markedly from the properties and processes at length scales directly accessible to human observation. This scale-dependent behaviour is possible in both directions; towards very large and very small scales. Scientists explore the frontiers of these extreme length scales in an effort to gain insight into yet unknown properties and processes. While the exploration of larger scales has been established since the Renaissance era, a comprehensive investigation of small scales was impeded by the limitations of optical microscopy. These imitations were overcome in the 20th century. Since then, a continuous series of developments in analytical power has taken place. Today these developments allow studies of properties and processes even at the molecular or atomic scale (often referred to as nanoscience). These modern nanoscientific possibilities have triggered new innovative projects in geosciences, providing fascinating insights into small scales. Therefore, nanogeoscience has become a very important geoscientific subdiscipline.
Focused ion beam (FIB): site-specific sample preparation, nano-analysis, nano-characterization and nano-machining
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Published:January 01, 2010
Abstract
Focused gallium ion beam devices were developed simultaneously at the University of Chicago and at the Oregon Graduate Institute in the mid-1970s. Micron-sized structures were milled from integrated circuits applying a high-current-density focused ion beam from a liquid metal ion source (LMIS) (Puretz et al., 1984). Previously, focused ion beam (FIB) was used preferentially in the semiconductor industry. Typical applications are quality control, wafer repair and microelectronic failure analysis. In the late 1980s and the early 1990s transmission electron microscope (TEM) foil preparation with FIB was introduced. The great success of that technique was the unique ability of FIB to prepare site-specific TEM foils (Kirk et al., 1989; Young et al., 1990; Basile et al., 1992; Overwijk et al., 1993). The publications listed describe the procedure: how to remove the foil from the excavation site, the ex situ lift-out technique, which later was improved by Giannuzzi et al. (1997). a summary of the FIB technique was presented by Orloff et al. (2003), and by Giannuzzi and Stevie (2005).
Application of FIB in the geosciences began in the early 2000s (Wirth, 2000, 2001; Dobrzhinetskaya et al., 2001; Dobrzhinetskaya & Green, 2001; Heaney et al., 2001; Dobrzhinetskaya et al., 2002; Wirth, 2002; Lee et al., 2003; Dobrzhinetskaya et al., 2003; Wirth, 2003; Graham et al., 2004; Wirth, 2004, 2005; Smith et al., 2006). at present, the major application of FIB in geosciences is site-specific TEM foil pre paration, though the technique is being used increasingly for other purposes such as micro machining of diamonds, specimen preparation for infrared (IR) spectroscopy and 3D cross-sectioning. The hardness contrast in multiphase materials, a major problem with conventional argon ion milling, is overcome with FIB. Interfaces are thinned preferentially by conventional argon ion milling because the interface region deviates in chemical composition and bonding from the bulk crystal structure. Interfaces are not thinned preferentially by the FIB method (Wirth, 2004; heinemann et al., 2005; Seydoux-Guillaume et al., 2003).