@article {2366,
	title = {Direct electron detection for EBSD of low symmetry \& beam sensitive ceramics},
	journal = {Ultramicroscopy},
	volume = {268},
	year = {2025},
	pages = {114079},
	abstract = {<p>
	Electron backscatter diffraction (EBSD) is a powerful tool for determining the orientations of near-surface grains in engineering materials. However, many ceramics present challenges for routine EBSD data collection and indexing due to small grain sizes, high crack densities, beam and charge sensitivities, low crystal symmetries, and pseudo-symmetric pattern variants. Micro-cracked monoclinic hafnia, tetragonal hafnon, and hafnia/hafnon composites exhibit all such features, and are used in the present work to show the efficacy of a novel workflow based on a direct detecting EBSD sensor and a state-of-the-art pattern indexing approach. At 5 and 10 keV primary beam energies (where beam-induced damage and surface charge accumulation are minimal), the direct electron detector produces superior diffraction patterns with 10x lower doses compared to a phosphor-coupled indirect detector. Further, pseudo-symmetric variant-related indexing errors from a Hough-based approach (which account for at least 4\%-14\% of map areas) are easily resolved by dictionary indexing. In short, the workflow unlocks fundamentally new opportunities to characterize materials historically unsuited for EBSD.
</p>
},
	keywords = {Beam sensitive materials, Ceramics, Dictionary indexing, Direct electron detection, Electron backscatter diffraction},
	author = {Della Ventura, Nicol{\`o} M and Ericks, Andrew R and Echlin, McLean P and Moore, Kalani and Pollock, Tresa M and Begley, Matthew R and Zok, Frank W and De Graef, Marc and Gianola, Daniel S}
}
@article {2416,
	title = {Energy-resolved EBSD using a monolithic direct electron detector},
	year = {2025},
	abstract = {<p>
	Accurate quantification of the energy distribution of backscattered electrons (BSEs) contributing to electron backscatter diffraction (EBSD) patterns remains as an active challenge. This study introduces an energy-resolved EBSD methodology based on a monolithic active pixel sensor direct electron detector and an electron-counting algorithm to enable the energy quantification of individual BSEs, providing direct measurements of electron energy spectra within diffraction patterns. Following detector calibration of the detector signal as a function of primary beam energy, measurements using a 12 keV primary beam on Si(100) reveal a broad BSE energy distribution across the diffraction pattern, extending down to 3 keV. Furthermore, an angular dependence in the weighted average BSE energy is observed, closely matching predictions from Monte Carlo simulations. Pixel-resolved energy maps reveal subtle modulations at Kikuchi band edges, offering insights into the backscattering process. By applying energy filtering within spectral windows as narrow as 2 keV centered on the primary beam energy, significant enhancement in pattern clarity and high-frequency detail is observed. Notably, electrons in the 2\&ndash;8 keV range, despite having undergone substantial energy loss (\&Delta;E = 4\&ndash;10 keV), still produce Kikuchi patterns. By enabling energy determination at the single-electron level, this approach introduces a versatile tool-set for expanding the quantitative capabilities of EBSD, thereby offering the potential to deepen the understanding of diffraction contrast mechanisms and to advance the precision of crystallographic measurements.
</p>
},
	author = {Della Ventura, Nicol{\`o} M and Moore, Kalani and Echlin, McLean P and Begley, Matthew R and Pollock, Tresa M and De Graef, Marc and Gianola, Daniel S}
}
