Determination of the atomic width of an APB in ordered CoPt using quantified HAADF-STEM

Phase equilibria among η-Fe 2 Al 5 and its higher-ordered phasesPhase equilibria among the η-Fe 2 Al 5 phase and its higher-ordered phases with the η framework structure were determined experimentally. The solubility range of the η phase at elevated temperature does not differ remarkably from that in previous studies, but this phase is found to undergo complicated phase transformations upon cooling. Four phases are present, namely η', η'', η''' and η m , with higher-order atomic orderings in the c-axis chain sites of the orthorhombic crystal structure of the parent η phase. The η'' and η''' phases form on the Al-poor and Al-rich sides, respectively, in equilibrium with the ζ-FeAl 2 phase below ~415 °C and θ-Fe 4 Al 13 phase below ~405 °C. The η' and η m phases become stable below 312 °C and 343 °C with the peritectoid reactions η' → η m + η''' and η m → η + η'', respectively. The η phase is not stable below 331 °C with the eutectoid reaction of η m + η''' → η. On the basis of these findings, we unraveled the phase equilibria among the η-Fe 2 Al 5 phase and its higher-ordered phases with the η framework structure.

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“…This value is within reason compared with reported  values in different ordered alloy systems [29][30][31].…”

Section: Refinement Of Crystal Structure Of η'' Phase With Finite Antiphase Boundary Width Modelsupporting

confidence: 87%

Phase equilibria among η-Fe₂Al₅ and its higher-ordered phases

Hamada

Higashi

Niitsu

et al. 2021

Science and Technology of Advanced Materials

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“…Moreover, by applying the quantitative HAADF (qHAADF) image analysis algorithm, developed by Molina et al [17], it is possible to correlate effectively HAADF intensity and atomic column composition in III–V ternary semiconductor materials [12, 16, 18] and consequently in GaAsBi compounds. Additionally, high-resolution HAADF-STEM images offer information about crystalline quality [19–22]. …”

Section: Introductionmentioning

confidence: 99%

Analysis of Bi Distribution in Epitaxial GaAsBi by Aberration-Corrected HAADF-STEM

et al. 2018

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The Bi content in GaAs/GaAs1 − xBix/GaAs heterostructures grown by molecular beam epitaxy at a substrate temperature close to 340 °C is investigated by aberration-corrected high-angle annular dark-field techniques. The analysis at low magnification of high-angle annular dark-field scanning transmission electron microscopy images, corroborated by EDX analysis, revealed planar defect-free layers and a non-homogeneous Bi distribution at the interfaces and within the GaAsBi layer. At high magnification, the qHAADF analysis confirmed the inhomogeneous distribution and Bi segregation at the GaAsBi/GaAs interface at low Bi flux and distorted dumbbell shape in areas with higher Bi content. At higher Bi flux, the size of the Bi gathering increases leading to roughly equiaxial Bi-rich particles faceted along zinc blende {111} and uniformly dispersed around the matrix and interfaces. FFT analysis checks the coexistence of two phases in some clusters: a rhombohedral pure Bi (rh-Bi) one surrounded by a zinc blende GaAs1 − xBix matrix. Clusters may be affecting to the local lattice relaxation and leading to a partially relaxed GaAsBi/GaAs system, in good agreement with XRD analysis.

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“…Quantitative STEM has been used to achieve atom counting in the beam direction, [14] location of individual dopant atoms in three-dimensions, [15,16] and characterization of chemical ordering on the atomic-scale. [17][18][19][20] All of these methods have relied on the intensity of atomic columns in high-angle annular dark field (HAADF) STEM images. In this letter, we will show that additional parameters, including specimen thickness and atomic-scale compositional analysis are necessary in combination with simulations to characterize atomic-scale ordering along the path of the electron beam.…”

mentioning

confidence: 99%

Quantitative STEM Imaging of Order-Disorder Phenomena in Double Perovskite Thin Films

et al. 2016

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Determination of the atomic width of an APB in ordered CoPt using quantified HAADF-STEM

Cited by 16 publications

References 21 publications

Phase equilibria among η-Fe₂Al₅ and its higher-ordered phases

Phase equilibria among η-Fe₂Al₅ and its higher-ordered phases

Analysis of Bi Distribution in Epitaxial GaAsBi by Aberration-Corrected HAADF-STEM

Quantitative STEM Imaging of Order-Disorder Phenomena in Double Perovskite Thin Films

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Determination of the atomic width of an APB in ordered CoPt using quantified HAADF-STEM

Cited by 16 publications

References 21 publications

Phase equilibria among η-Fe2Al5 and its higher-ordered phases

Phase equilibria among η-Fe2Al5 and its higher-ordered phases

Analysis of Bi Distribution in Epitaxial GaAsBi by Aberration-Corrected HAADF-STEM

Quantitative STEM Imaging of Order-Disorder Phenomena in Double Perovskite Thin Films

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Product

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Phase equilibria among η-Fe₂Al₅ and its higher-ordered phases

Phase equilibria among η-Fe₂Al₅ and its higher-ordered phases