Generational assessment of EBSD detectors for cross-correlation-based analysis: From scintillators to direct detection.

Introduced over ten years ago, cross-correlation-based electron backscatter diffraction has enabled high precision measurements of crystallographic rotations and elastic strain gradients at high spatial resolution. Since that time, there have been remarkable improvements in electron detector technology, including the advent of ultra-high speed detectors and the commercialization of direct detectors. In this study, we assess the efficacy of multiple generations of electron detectors for cross-correlation-based analysis using a single crystal Si sample as a reference.

Direct Observation of Grain-Boundary-Migration-Assisted Radiation Damage Healing in Ultrafine Grained Gold under Mechanical Stress.

Nanostructured metals are a promising class of radiation-tolerant materials. A large volume fraction of grain boundaries (GBs) can provide plenty of sinks for radiation damage, and understanding the underlying healing mechanisms is key to developing more effective radiation tolerant materials. Here, we observe radiation damage absorption by stress-assisted GB migration in ultrafine-grained Au thin films using a quantitative transmission electron microscopy nanomechanical testing technique.

Ferrielectricity in the Archetypal Antiferroelectric, PbZrO.

Antiferroelectric materials, where the transition between antipolar and polar phase is controlled by external electric fields, offer exceptional energy storage capacity with high efficiencies, giant electrocaloric effect, and superb electromechanical response. PbZrO is the first discovered and the archetypal antiferroelectric material. Nonetheless, substantial challenges in processing phase pure PbZrO have limited studies of the undoped composition, hindering understanding of the phase transitions in this material or unraveling the controversial origins of a low-field ferroelectric phase observed in lead zirconate thin films.

Remote Oxygen Scavenging of the Interfacial Oxide Layer in Ferroelectric Hafnium-Zirconium Oxide-Based Metal-Oxide-Semiconductor Structures.

Discovery of ferroelectricity in HfO has sparked a lot of interest in its use in memory and logic due to its CMOS compatibility and scalability. Devices that use ferroelectric HfO are being investigated; for example, the ferroelectric field-effect transistor (FEFET) is one of the leading candidates for next generation memory technology, due to its area, energy efficiency and fast operation. In an FEFET, a ferroelectric layer is deposited on Si, with an SiO layer of ∼1 nm thickness inevitably forming at the interface.

Local Epitaxial Templating Effects in Ferroelectric and Antiferroelectric ZrO.

Nanoscale polycrystalline thin-film heterostructures are central to microelectronics, for example, metals used as interconnects and high-K oxides used in dynamic random-access memories (DRAMs). The polycrystalline microstructure and overall functional response therein are often dominated by the underlying substrate or layer, which, however, is poorly understood due to the difficulty of characterizing microstructural correlations at a statistically meaningful scale. Here, an automated, high-throughput method, based on the nanobeam electron diffraction technique, is introduced to investigate orientational relations and correlations between crystallinity of materials in polycrystalline heterostructures over a length scale of microns, containing several hundred individual grains.

Antiferroelectric negative capacitance from a structural phase transition in zirconia.

Crystalline materials with broken inversion symmetry can exhibit a spontaneous electric polarization, which originates from a microscopic electric dipole moment. Long-range polar or anti-polar order of such permanent dipoles gives rise to ferroelectricity or antiferroelectricity, respectively. However, the recently discovered antiferroelectrics of fluorite structure (HfO and ZrO) are different: A non-polar phase transforms into a polar phase by spontaneous inversion symmetry breaking upon the application of an electric field.

Influence of misorientation angle and local dislocation density on β-phase distribution in Al 5xxx alloys.

Al-Mg alloys undergo sensitization when exposed to elevated temperatures, making them susceptible to intergranular corrosion and stress corrosion cracking. Most of the existing research on microstructure effects on sensitization is centered on the effect of intrinsic grain boundary characteristics such as misorientation angle and coincident site lattice (CSL) values. Very few studies have systematically investigated the influence of extrinsic characteristics such as dislocation density.

Correction: TEM measurement of activation volume in ultrafine grained gold.

Correction for 'In situ TEM measurement of activation volume in ultrafine grained gold' by Saurabh Gupta et al., Nanoscale, 2020, 12, 7146-7158, DOI: 10.1039/D0NR01874K.

In situ TEM measurement of activation volume in ultrafine grained gold.

A micro-electromechanical system (MEMS) based technique is demonstrated for in situ transmission electron microscopy (TEM) measurements of stress relaxation with simultaneous observation of the underlying plastic deformation processes. True activation volumes are determined from repeated stress relaxation transients and thus provide a signature parameter of the governing mechanisms of plastic deformation. The technique is demonstrated with 100 nm-thick ultrafine-grained gold microspecimens under uniaxial tension.

Investigating local oxidation processes in Fe thin films in a water vapor environment by in situ liquid cell TEM.

Automated image recognition and analysis techniques were combined with liquid cell transmission electron microscopy to explore the oxidation kinetics of nanocrystalline Fe thin films in a water vapor environment. From in situ microscopy experiments, localized oxidation was observed to initiate in the film then propagate in an unsteady fashion, alternatingly arresting and progressing. The oxidation front propagation occurred via new oxidation sites initiating 10s of nm ahead of the existing front rather than through a continuous expansion mechanism.

Pattern center determination in electron backscatter diffraction microscopy.

The pattern center of an electron backscatter diffraction (EBSD) image indicates the relative position of the image with reference to the interaction volume of the sample. As interest grows in high-resolution EBSD techniques, accurate knowledge of this position is essential for precise interpretation of the EBSD features. In a typical EBSD framework, Kikuchi bands are recorded on a phosphor screen.

Reply to comment by Maurice et al. in response to "Bragg's Law Diffraction Simulations for Electron Backscatter Diffraction Analysis".

A reply to Maurice et al.'s comment on "Bragg's Law Diffraction Simulations for Electron Backscatter Diffraction" is presented. A new method for microscope geometry calibration is briefly presented.

Bragg's Law diffraction simulations for electron backscatter diffraction analysis.

In 2006, Angus Wilkinson introduced a cross-correlation-based electron backscatter diffraction (EBSD) texture analysis system capable of measuring lattice rotations and elastic strains to high resolution. A variation of the cross-correlation method is introduced using Bragg's Law-based simulated EBSD patterns as strain free reference patterns that facilitates the use of the cross-correlation method with polycrystalline materials. The lattice state is found by comparing simulated patterns to collected patterns at a number of regions on the pattern using the cross-correlation function and calculating the deformation from the measured shifts of each region.