Application Of Electron Backscatter Diffraction Research Articles

Exploring electron backscatter diffraction analysis as a tool for understanding stromatolite: Quantitative description of Cretaceous lacustrine stromatolite reveals formative processes and high‐resolution climatic cycles

AbstractLacustrine stromatolites serve as important archives for recording environmental changes, and the detailed examination of their microfabrics is essential for understanding their formative processes and the environmental changes embedded within them. This study explored the application of Electron Backscatter Diffraction combined with Energy‐Dispersive X‐ray Spectroscopy to investigate a well‐preserved middle Cretaceous lacustrine stromatolite from south‐eastern Korea, unveiling ultra‐high‐resolution sedimentary processes that are often challenging to observe using conventional methods. Two types of microsparitic layers and one type of crystalline layer are distinguished based on their texture, crystal morphology and elemental composition. Both microsparitic layers are micrometre‐thick and are characterized by poorly co‐oriented calcite grains, but differ in their composition. Type 1 is depleted in magnesium but enriched in detrital elements such as silicon and aluminium, likely originating from the trapping and binding of detrital sediments on microbial mats during rainy seasons. In contrast, type 2 is enriched in magnesium but devoid of detrital elements, interpreted to have formed by the precipitation of calcium carbonate during dry seasons. The crystalline layers comprise fan‐shaped calcite crystals (ca 500 μm in length) with radiating internal structures, with their c‐axes oriented perpendicular to the stromatolite layers. These structures resemble those observed in some modern freshwater stromatolites, which are interpreted as imprints of cyanobacterial fascicules. While the cyclic occurrence of types 1 and 2 microsparitic layers might imply annual seasonal cycles, the less frequent crystalline layers are interpreted as a result of environmental changes occurring every 27 to 30 years. This is the first study to apply Electron Backscatter Diffraction to stromatolites, showcasing its potential in unravelling both the formative and diagenetic processes of ancient stromatolites.

Application of electron backscatter diffraction in facet crystalline orientation study of Al-Cu-Fe alloy

Facets are flat faces of a single crystal, which are typically parallel to the low-energy lattice planes. The orientation of a facet can sometimes be determined by simple visual examination, as in the case of the gemstone industry. Facets on microscale particles often do not correspond to the expected results of equilibrium, and the smaller physical size presents a challenge in observation. Using a facet observed on spherical particles of 20 μm diameter in alloys of Al60Cu25Fe15 composition as an example, a procedure to determine facet orientation based on the combined usage of Scanning Electron Microscope (SEM) and Electron Backscatter Diffraction (EBSD) has been proposed and tested. Out of three types of facets found, the crystalline orientation of one type is determined by two approaches: by examination of facet relative layout and by orientation analysis based on the usage of SEM-EBSD. The former is along the traditional line of visual examination and the latter represents an attempt to expand the application of EBSD in a different field. Both approaches proved that the surface of the facet is parallel to the {100} lattice plane of a cubic phase. The experimental details and the strength of SEM-EBSD in such application are discussed.

Application of electron backscatter diffraction in the SEM to textural problems of coated high-temperature superconductors

Abstract YBa2Cu3O7– δ (YBCO) is a high-temperature superconductor (HTS) with unique characteristics for use in electrical engineering. The structure and the transport properties of the cuprate superconductor are reviewed. The key issues in HTS wire technology, viz. texture tailoring and grain boundary engineering of the polycrystalline material to be used in technical devices, are discussed. A production route is described to fabricate long lengths of highly aligned YBCO films on cube-textured nickel and nickel alloy substrates. Electron backscatter diffraction in the scanning electron microscope is used to control the process → texture relationship in developing the sheet material as well as the epitaxy and phase stability of the YBCO film.

Palaeozoic stromatoporoids and chaetetids analysed using electron backscatter diffraction (EBSD); implications for original mineralogy and microstructure

Palaeozoic hypercalcified sponges were ubiquitous Ordovician—Devonian reef builders but, despite their rich fossil record, their original skeletal mineralogy and microstructure remain poorly understood. This study provides the first application of electron backscatter diffraction (EBSD) to analyse skeletal structure of Silurian and Devonian stromatoporoids. The two Silurian and two Devonian stromatoporoid taxa selected are typical of stromatoporoids in showing poor preservation. A reference sample of an exceptionally well-preserved hypercalcified chaetetid sponge from the Carboniferous Buckhorn Asphalt Quarry (a fossil lagerstätte renowned for its preservation of skeletal microstructures) contains evidence that its skeleton comprised distinct bundles of single-crystal fibres, similar to modern hypercalcifying sponges. Similar bundles of crystal fibres are proposed here as the original microstructure of stromatoporoids, and acted as precursors to the coarse fibrous calcitic overprinting recrystallisation that is orientated normal to the growth layers, seen in all stromatoporoids viewed in cross-polarised light. The studied stromatoporoids show pronounced microporosity and micro-dolomite inclusions which are circumstantial evidence of an original composition of high-Mg calcite (HMC). We propose that the evidence of fibrous structures might be linked to inclusions of hydrated amorphous calcium carbonate (ACC·H2O) in the skeleton at the time of early diagenesis, as occurs in modern calcified sponges. The possible HMC skeletal composition of Palaeozoic stromatoporoids supports earlier views that the mineral composition of hypercalcifying reef builders is linked to Phanerozoic oscillations in the ratio of Mg:Ca, expressed as aragonite-calcite seas; stromatoporoids thrived in times of calcite-seas.

The Application of Electron Backscatter Diffraction on Halide Perovskite Materials

AbstractRecently, the application of electron backscatter diffraction (EBSD) in halide perovskites has enabled the correlation of the micro‐structural arrangement of polycrystalline grains with other properties (optical, electrical, mechanical, and chemical) in a “pixel‐by‐pixel” approach. Most studies so far have used an ultra‐sensitive electron beam detector that has sensitivity thousands of times higher than a traditional scintillator screen and charge coupled device camera, enabling much lower beam currents. An alternative approach has been the use of low vacuum measurement conditions to avoid charge buildup that leads to damage. This review focuses on introducing the classical EBSD technique to the halide perovskite community, where it has been highly underutilized due to beaminduced damage in these relatively unstable materials. Recent research is used to dispel some common misconceptions about grain boundaries in halide perovskites and highlight what has been learned by comparing and correlating EBSD with other techniques. Additionally, the remaining limitations, development challenges, and future of the EBSD technique for halide perovskites are discussed. Successful utilization of the EBSD technique as a common characterization tool in the halide perovskite community will enable scientists and engineers to develop maps of cross correlated properties, helping to unlock the full potential of this complex material system.

The Application of Electron Backscatter Diffraction for Investigating Intra-Particle Grain Architectures and Boundaries in Lithium Ion Electrodes

The performance and degradation of layered cathode materials for lithium-ion batteries are largely governed by their morphological and crystallographic properties. A comprehensive tool to spatially characterize grain architectures in electrode particles is needed to understand solid-state lithium transport and the efficacy of particles to avoid lithiation heterogeneities and strain-induced degradation. Here, we apply electron backscatter diffraction on LiNi0.5Mn0.3Co0.2O2 particle cross-sections to spatially describe intra-particle grain architectures. A method for segmenting, labelling, and quantifying morphological properties of distinct grains is developed and applied. Crystallographic orientations are measured for each grain and the spatial distribution of grain orientations is quantified with a specific focus on describing the plane along which lithium transports, accounting for inter-grain lithiation barriers and for favorable inward lithiation of the particle. The extension from 2D to 3D descriptions of grain morphologies and orientations to predict lithiation inefficiencies is discussed, as well as a method to quantify the ideality of grain architectures for high-rate and efficient operation.

EBSD Characterization of Specific Microstructures in RE-BCO Superconductors

Using the electron backscatter diffraction (EBSD) technique, we analyze in this contribution the microstructure of YBa2Cu3O x (YBCO) thick films with embedded a -axis oriented grains. The YBCO films were prepared by liquid phase epitaxy in air using NdGaO3 substrates. Using this technique, a / c -grain boundaries (GBs) with a well-defined facet of the YBCO film characterized by a single crystalline nature are obtained. This type of GB is very important for the basic physics of GBs in high- T c superconductor materials, and will contribute to a better understanding of GBs also in bulk materials. The application of EBSD to the analysis of a / c -GBs in YBCO requires a high Kikuchi pattern quality (i.e., image quality) to enable a proper distinction of the orientation, as the a -axis corresponds to about one-third of the c -axis, which can cause a misinterpretation of the resulting data. Having solved this problem, the EBSD-based determination of the GB misorientation angles directly proof the specific grain orientation achieved in the film growth.

Advanced crystallographic study of the columnar growth of YZS coatings produced by PS-PVD

In the Plasma Spray-Physical Vapor Deposition (PS-PVD) process, columnar structured coatings are deposited mainly from the vapor phase due to the intensive evaporation of the feedstock powder. This paper highlights the application of electron backscatter diffraction (EBSD) for the characterization of columnar structured ceramic PS-PVD coatings. The growth processes of PS-PVD coatings could be elucidated, developing from small equiaxed crystals to large columnar crystals. Furthermore, the main effect of the torch swing on coating deposition could be the interruption of crystal growth and thus repeated nucleation. This may have a similar effect as slowly rotating the substrate in Electron Beam-Physical Vapor Deposition (EB-PVD).

Application of Electron Backscatter Diffraction to evaluate the ASR risk of concrete aggregates

Alkali-Silica Reaction (ASR) is a frequent cause of reduced concrete durability. Eliminating the application of alkali reactive aggregates would reduce the quantity of ASR concrete deterioration in the field.This study introduces an Electron Backscatter Diffraction (EBSD) technique to distinguish the ASR risk of slow-late reacting aggregates by measuring microstructural properties of quartz. Quantifying the amount of quartz grain boundaries and the associated misorientation of grains can thereby be used to differentiate microstructures bearing an ASR risk. It is also shown that dissolution of quartz in high pH environments occurs along quartz grain and subgrain boundaries.Results of EBSD analysis are compared with ASR performance testing on concrete prisms and optical light microscopy characterization of quartz microstructure. EBSD opens new possibilities to quantitatively characterize microstructure of quartz in concrete aggregates with respect to ASR. This leads to a better understanding on the actual cause of ASR.

Electron backscatter diffraction beyond the mainstream

We present special applications of electron backscatter diffraction (EBSD) which aim to overcome some of the limitations of this technique as it is currently applied in the scanning electron microscope. We stress that the raw EBSD signal carries additional information which is useful beyond the conventional orientation determination. The background signal underlying the backscattered Kikuchi diffraction (BKD) patterns reflects the chemical composition and surface topography but also contains channeling‐in information which is used for qualitative real‐time orientation imaging using various backscattered electron signals. A significantly improved orientation precision can be achieved when dynamically simulated pattern are matched to the experimental BKD patterns. The breaking of Friedel's rule makes it possible to obtain orientation mappings with respect to the point‐group symmetries. Finally, we discuss the determination of lattice parameters from individual BKD patterns. Subgrain structure in a single quartz grain. The increased noise level in the left map reflects the lower precision of a standard orientation determination using band detection by the Hough transform. The right map results from the same experimental raw data after orientation refinement using a pattern matching approach. The colors correspond an adapted inverse pole figure color key with a maximum angular deviation of about 2° from the mean orientation.

Application of electron backscatter diffraction (EBSD) to quasicrystal-containing microstructures in the Mg-Cd-Yb system

We develop a new analysis system for identifying orientation of an icosahedral quasicrystal (iQc) in a SEM installed with an electron backscatter diffraction (EBSD) instrument. The system is successfully applied to determine the orientation of any given iQc grain by reading and assigning the Kikuchi bands obtained with the EBSD. This enables us to analyze relative orientations of iQc and αMg grains in a eutectic structure obtained through a unidirectional solidification process for the Mg-Cd-Yb system. According to EBSD analysis, growth direction of the eutectic structure is shown to be clearly parallel to a two-fold axis of the iQc and {10-10} of αMg, and a unique orientation relationship in iQc and αMg grains is verified in all iQc-αMg coexisting regions. The similarity between primary inter-planar spacings of the iQc and αMg phases is a key factor for stabilizing the interface of two phases and favoring the formation of eutectic structure. This stabilization mechanism is supported by a simple argument on the energetics of a quasiperiodic/periodic lattice interface.

EBSD analysis of rhombohedral twinning in hematite crystals of naturally deformed iron formations

The rhombohedral twinning in hematite has an important role in the accommodation of the deformation of hematite single crystals and hematite aggregates. It is a contact twinning and occurs as lamellae parallel to the \{10{\overline 1}2\} planes of hematite as a result of twin gliding on such planes. On account of the recent applications of electron backscatter diffraction (EBSD) techniques in a wide range of microstructural studies, the determination of symmetry operations that relate crystals in a deformed crystalline aggregate is crucial for the full textural characterization. This study presents an EBSD-based crystallographic analysis of the rhombohedral twinning on hematite crystals of a naturally deformed banded iron formation. Manipulations of theoretical pole figures depicting the symmetry relation of the rhombohedral twinning and misorientation and crystallographic data obtained by EBSD are used to establish the rotational relationship between twin and parent crystals. A method for determining pairs of axes and angles of rotation was developed which can be extended to any other twin laws or misorientation patterns in any other crystal system. It was found that the hematite rhombohedral twins are related to the parent crystal by an approximately 85° rotation about the 〈02{\overline 2}1〉 directions. Hence it could be determined that this consists of a macroscopic twinning element which is an alternative to the conventional ones used to describe the symmetry of the twin. It also matches microscopic twinning elements for the rhomb twinning law. Additionally, this method allows the determination of the crystallographic orientation of the twin lamellae and which particular 〈02{\overline 2}1〉 axis satisfies the 85°〈02{\overline 2}1〉 pair of rotation. The use of an unambiguous angle–axis pair of rotation allows the identification of twin boundaries in complex and finely grained aggregates and the distinction of twinning laws in a particular crystal.

EBSD Analysis of Tungsten-Filament Carburization During the Hot-Wire CVD of Multi-Walled Carbon Nanotubes

Filament condition during hot-wire chemical vapor deposition conditions of multi-walled carbon nanotubes is a major concern for a stable deposition process. We report on the novel application of electron backscatter diffraction to characterize the carburization of tungsten filaments. During the synthesis, the W-filaments transform to W2C and WC. W-carbide growth followed a parabolic behavior corresponding to the diffusion of C as the rate-determining step. The grain size of W, W2C, and WC increases with longer exposure time and increasing filament temperature. The grain size of the recrystallizing W-core and W2C phase grows from the perimeter inwardly and this phenomenon is enhanced at filament temperatures in excess of 1,400°C. Cracks appear at filament temperatures >1,600°C, accompanied by a reduction in the filament operational lifetime. The increase of the W2C and recrystallized W-core grain size from the perimeter inwardly is ascribed to a thermal gradient within the filament, which in turn influences the hardness measurements and crack formation.

Application of Electron Backscatter Diffraction (EBSD) for Crystallographic Characterization of Aluminum-Doped Zinc Oxide Sputtered Films

Zinc Oxide is a wide band-gap compound semiconductor that has been used in optoelectronic and photovoltaic applications due to its good electrical and optical properties. Aluminium has been an efficient n-type dopant for ZnO to produce low resistivity films and high transparency to visible light. In addition, the improvement of these properties also depends on the morphology, crystalline structure and deposition parameters. In this work, ZnO:Al films were produced by d.c. pulsed magnetron sputtering deposition from a ZnO ceramic target (2.0 wt% Al2O3) on glass substrates, at a temperature of 250 ºC.The crystallographic orientation of aluminum doped zinc oxide (ZnO:Al) thin films has been studied by Electron Backscatter Diffraction (EBSD) technique. EBSD coupled with Scanning Electron Microscopy (SEM) is a powerful tool for the microstructural and crystallographic characterization of a wide range of materials.The investigation by EBSD technique of such films presents some challenges since this analysis requires a flat and smooth surface. This is a necessary condition to avoid any shadow effects during the experiments performed with high tilting conditions (70º). This is also essential to ensure a good control of the three dimensional projection of the crystalline axes on the geometrical references related to the sample.Crystalline texture is described by the inverse pole figure (IPF) maps (Figure 1). Through EBSD analysis it was observed that the external surface of the film presents a strong texture on the basal plane orientation (grains highlighted in red colour). Furthermore it was possible to verify that the grain size strongly depends on the deposition time (Figure 1 (a) and (b)). The electrical and optical film properties improve with increasing of the grain size, which can be mainly, attributed to the decrease in scattering grain boundaries which leads to an increasing in carrier mobility (Figure 2).The authors kindly acknowledge the financial support from the Portuguese Foundation for Science and Technology (FCT) scientific program for the National Network of Electron Microscopy (RNME) EDE/1511/RME/2005.

Advanced Electron Backscatter Diffraction Applications and Techniques

Since the first automated electron backscatter diffraction (EBSD) results were attained 22 years ago, EBSD has become a common characterization technique in materials laboratories around the world. This has led to advancements and new understanding in not just crystallography but also in microstructural evolution, phase transformations, defects and dislocations, mechanical behavior, failure, and other materials phenomena. As a complement to scanning electron microscopy (SEM), EBSD is accessible and available to many researchers with little additional sample preparation. With improvements to both SEM and EBSD, it is now possible to analyze large areas for statistically significant data, and as precision increases, higher resolutions and smaller length scales have become accessible. EBSD analyses are also being combined with other characterization and analysis techniques to provide new insights. Although EBSD has matured and measurements have become more commonplace, new techniques, applications, and approaches continue to be introduced regularly. This collection of articles focuses on the versatility of EBSD in the range of materials systems presented, as well as on new techniques and applications of EBSD for materials characterization. Examples of the combination of EBSD with other characterization techniques include the supplementation and enhancement of EBSD data by transmission electron microscopy (TEM), atomic force microscopy (AFM), and electron channeling contrast imaging. Novel approaches to strain measurements, and the analysis of stacking faults, defects, and dislocations are also presented. The versatility of EBSD is demonstrated in the range of materials systems represented in these articles; EBSD analyses of conventional polycrystalline metals and alloys, novel lightweight alloys, second phase precipitates, and the complex structures of thin film solar cells are presented. The article from D. Abou-Ras and his co-workers provides an overview of the application of EBSD on thin-film solar cells. Of particular interest is the integration of EBSD results with several scanning probe microscopy techniques for correlating properties critical to photovoltaic performance with the crystallographic orientation aspects of the observed microstructures. I. Gutierrez-Urrutia, S. Zaefferer, and D. Raabe have reviewed a novel application of EBSD for imaging crystal defects, such as dislocations, cells, and stacking faults. EBSD is used to determine the optimal diffraction conditions for electron channeling contrast imaging to elucidate dislocation substructures similar to those observed using conventional TEM diffraction. Z. Chen and C.J. Boehlert combine EBSD with AFM to quantify deformation in an AZ31 magnesium alloy, noting that grain boundary sliding has a significant contribution. In the article by T. Ben Britton and colleagues, elastic strains are measured using highresolution, cross-correlation-based EBSD, presenting three examples of this exciting technique. Finally, Seiichi Suzuki presents a systematic overview of the transmission EBSD technique, which provides very high spatial resolution in orientation mapping. This collection of articles represents just a sampling of the new and exciting data being collected using EBSD, while also covering a breadth of work that illustrates both the utility and the potential of this important technique. As advancements continue to be made, we anticipate EBSD to fuel further innovative studies and bring exciting results in crystallography, microstructural evolution, materials processing, and microstructure quantification for years to come.

Electron Backscatter Diffraction: An Important Tool for Analyses of Structure–Property Relationships in Thin-Film Solar Cells

The present work gives an overview of the application of electron backscatter diffraction (EBSD) in the field of thin-film solar cells, which consist of stacks of polycrystalline layers on various rigid or flexible substrates. EBSD provides access to grain-size and local-orientation distributions, film textures, and grain-boundary types. By evaluation of the EBSD patterns within individual grains of the polycrystalline solar cell layers, microstrain distributions also can be obtained. These microstructural properties are of considerable interest for research and development of thin-film solar cells. Moreover, EBSD may be performed three-dimensionally, by alternating slicing of cross sections in a focused ion-beam machine and EBSD acquisition. To relate the microstructural properties to the electrical properties of individual layers as well as to the device performances of corresponding solar cells, EBSD can be combined with electron-beam-induced current and cathodoluminescence measurements and with various scanning-probe microscopy methods such as Kelvin-probe force, scanning spreading resistance, or scanning capacitance microscopy on identical specimen positions. Together with standard device characterization of thin-film solar cells, these scanning microscopy measurements provide the means for extensive analysis of structure–property relationships in solar-cell stacks with polycrystalline layers.

Microstructure of the paper nautilus (Argonauta nodosa) shell and the novel application of electron backscatter diffraction (EBSD) to address effects of ocean acidification

Electron backscatter diffraction (EBSD) is a powerful microscopic technique to characterise the crystallography of biomineralisation. Here, we use high-resolution EBSD to characterise one of the least studied shells in the ocean, the female argonaut brood chamber, and to examine the changes in shell microstructure in response to incubation in decreased pH conditions. The thin (225 μm) shell of Argonauta nodosa is magnesium calcite with an average magnesium content of ca. 5.1 Wt % MgCO3. EBSD and scanning electron microscopy (SEM) revealed that calcification of the shell is bidirectional with formation of irregular crystalline grains. Following a 2 week incubation in a range of pH treatments (pH, 8.1–7.2), shell fragment weight decreased by dissolution in pH ≤ 7.8. EBSD and SEM revealed altered shell crystallography and microstructure at pH ≤ 7.4 due to preferential etching down crystallite grain boundaries and a change in crystalline orientation on both the inner and outer shell surfaces. Our study highlights the value of EBSD for the detailed examination of biogenic carbonates and its potential use in the field of ocean acidification research.

Application of Electron Backscatter Diffraction to Shape Memory Alloys

This overview highlights very recent application of electron backscatter diffraction (EBSD) to shape memory alloys, as main investigation technique but also as ancillary technique for other characterization methods. Over the last two decades EBSD in the scanning electron microscope has become a powerful tool for the characterization of many materials and transformation. In the mean time, shape memory alloys (SMA) are continuously studied: from a theoretical point of view, in order to clarify unsolved fundamentals of their phase transformations and characterize or develop new SMA systems, and from an engineering point of view, to solve design and processing problems related to the continuously growing examples of applications. Application of EBSD to SMA, even if hindered by limitations generally found also in other metallic system when phase transformation and martensitic phases are involved, provided useful information for both research areas.

Application of Electron Backscatter Diffraction for Crystallographic Characterization of Tin Whiskers

Understanding the growth of whiskers or high aspect ratio features on substrates can be aided when the crystallography of the feature is known. This study has evaluated three methods that utilize electron backscatter diffraction (EBSD) for the determination of the crystallographic growth direction of an individual whisker. EBSD has traditionally been a technique applied to planar, polished samples, and thus the use of EBSD for out-of-surface features is somewhat more difficult and requires additional steps. One of the methods requires the whiskers to be removed from the substrate resulting in the loss of valuable physical growth relationships between the whisker and the substrate. The other two techniques do not suffer this disadvantage and provide the physical growth information as well as the crystallographic growth directions. The final choice of method depends on the information required. The accuracy and the advantages and disadvantages of each method are discussed.

Electron backscatter diffraction (EBSD) analyses of phyllosilicates in petrographic thin sections

Applications of electron backscatter diffraction (EBSD) to obtain crystallographic information of minerals in petrographic thin sections in mineralogy and petrology are increasing. However, platy phyllosilicates that mostly appear with their silicate layers terminated by the surface in the thin sections generally do not show sharp EBSD patterns in spite of gentle mechanical polishing. TEM examination indicated that this is due to crystal bending of phyllosilicates from the surface to a few micrometers in depth, caused by the polishing process. Ion beam etching commonly used to prepare TEM specimens was found to be applicable to remove the surface region with crystal bending. As a result, clear and sharp EBSD patterns were acquired from the phyllosilicates (micas, chlorite, etc.) in petrographic thin sections, by which their crystal orientations and polytypes were unambiguously determined.