The performance of polycrystalline CdTe photovoltaic thin films is expected to depend on the grain boundary density and corresponding grain size of the film microstructure. However, the electrical performance of grain boundaries within these films is not well understood, and can be beneficial, harmful, or neutral in terms of film performance. Electron backscatter diffraction has been used to characterize the grain size, grain boundary structure, and crystallographic texture of sputtered CdTe at varying deposition pressures before and after CdCl2 treatment in order to correlate performance with microstructure. Weak fiber textures were observed in the as-deposited films, with (111) textures present at lower deposition pressures and (110) textures observed at higher deposition pressures. The CdCl2-treated samples exhibited significant grain recrystallization with a high fraction of twin boundaries. Good correlation of solar cell efficiency was observed with twin-corrected grain size while poor correlation was found if the twin boundaries were considered as grain boundaries in the grain size determination. This implies that the twin boundaries are neutral with respect to recombination and carrier transport.

Electron backscatter diffraction (EBSD) has become a common technique for measuring crystallographic orientations at spatial resolutions on the order of tens of nanometers and at angular resolutions <0.1°. In a recent search of EBSD papers using Google Scholar™, 60% were found to address some aspect of deformation. Generally, deformation manifests itself in EBSD measurements by small local misorientations. An increase in the local misorientation is often observed near grain boundaries in deformed microstructures. This may be indicative of dislocation pile-up at the boundaries but could also be due to a loss of orientation precision in the EBSD measurements. When the electron beam is positioned at or near a grain boundary, the diffraction volume contains the crystal lattices from the two grains separated by the boundary. Thus, the resulting pattern will contain contributions from both lattices. Such mixed patterns can pose some challenge to the EBSD pattern band detection and indexing algorithms. Through analysis of experimental local misorientation data and simulated pattern mixing, this work shows that some of the rise in local misorientation is an artifact due to the mixed patterns at the boundary but that the rise due to physical phenomena is also observed.

Since the automation of the electron backscatter diffraction (EBSD) technique, EBSD systems have become commonplace in microscopy facilities within materials science and geology research laboratories around the world. The acceptance of the technique is primarily due to the capability of EBSD to aid the research scientist in understanding the crystallographic aspects of microstructure. There has been considerable interest in using EBSD to quantify strain at the submicron scale. To apply EBSD to the characterization of strain, it is important to understand what is practically possible and the underlying assumptions and limitations. This work reviews the current state of technology in terms of strain analysis using EBSD. First, the effects of both elastic and plastic strain on individual EBSD patterns will be considered. Second, the use of EBSD maps for characterizing plastic strain will be explored. Both the potential of the technique and its limitations will be discussed along with the sensitivity of various calculation and mapping parameters.

Teouma, an archaeological site on Efate Island, Vanuatu, features the earliest cemetery yet discovered of the colonizers of Remote Oceania, from the late second millennium B.C. In order to investigate potential migration of seventeen human individuals, we measured isotopes of strontium (87Sr/86Sr), oxygen (δ18O), and carbon (δ13C), as well as barium (Ba) and strontium (Sr) concentrations, in tooth enamel from skeletons excavated in the first two field seasons. The majority of individuals cluster with similar isotope and Ba/Sr ratios, consistent with a diet of marine resources supplemented with plants grown on the local basaltic soils. Four outliers, with distinctive 87Sr/86Sr and δ18O, are probably immigrants, three of which were buried in a distinctive position (supine, with the head to the south) with higher Ba/Sr and δ13C, consistent with a terrestrial, nonlocal diet. Among the probable immigrants was a male buried with the crania of three of the locally raised individuals on his chest.

The Gibeon meteorite is a differentiated iron meteorite that fell in Nambia, Africa in prehistoric times, with fragments spread over an area 70 miles wide and 230 miles long. The Gibeon fall was initially discovered in 1836, and hundreds of thousands of kilograms of fragments have been recovered. These fragments represent the iron core of a meteorite that cooled and crystallized over thousands of years (Norton 2002).

The microstructure of the Gibeon meteorite, which is primarily an iron-nickel alloy, consists of two phases: kamacite, a body-centered cubic material and taenite, a face-centered cubic material that metallurgists would refer to as ferrite and austenite respectively. This material initially crystallizes as taenite, and as the temperature decreases, transforms into kamacite. This meteorite is classified as a Fine Octahedrite (Of) with an average Nickel content of approximately 7.9%

Orientation mapping via automated analysis of Electron Backscatter Diffraction (EBSD) patterns has developed into an established microstructural analysis tool in the electron microscopy community. From the early 1990s, when this technique became commercially available, there has been a steady increase in the data acquisition rates as shown in Figure 1. Currently, orientation mapping speeds of over 200 analyzed patterns per second have been achieved. With these types of acquisition rates now available, the strategy on how to best use EBSD and orientation mapping has also shifted. Early adopters of this technique had to allocate hours of Scanning Electron Microscope (SEM) beam time in order to collect statistically significant data. With current technology, what was collected in hours can now be obtained in minutes. The goal of this article is to introduce this high-speed orientation mapping and present results illustrating the benefits of this capability.

Image quality (IQ) maps constructed from electron backscatter diffraction data provide useful visualizations of microstructure. The contrast in these maps arises from a variety of sources, including phase, strain, topography, and grain boundaries. IQ maps constructed using various IQ metrics are compared to identify the most prominent contrast mechanism for each metric. The conventional IQ metric was found to provide the superior grain boundary and strain contrast, whereas an IQ metric based on the average overall intensity of the diffraction patterns was found to provide better topological and phase contrast.

Automated analysis of Electron Backscatter Diffraction (EBSD) patterns for orientation imaging and phase identification in materials and earth sciences has become a widely accepted microstructural analysis tool. To briefly review, EBSD is a scanning electron microscope (SEM) based technique where the sample is tilted approximately 70 degrees and the electron beam is positioned in an analytical spot-mode within a selected grain. An EBSD pattern is formed due to the diffraction of the electron beam by select crystallographic planes within the material. The EBSD pattern is representative of both the phase and crystallographic orientation of the selected area. The pattern is imaged by a phosphor screen and recorded with a digital CCD camera and then analyzed.