Characterization of individual stacking faults in a wurtzite GaAs nanowire by nanobeam X-ray diffraction

Davtyan, Arman; Lehmann, Sebastian; Kriegner, Dominik; Zamani, Reza; Dick, Kimberly A.; Bahrami, Danial; AlHassan, Ali; Leake, Steven; Pietsch, U.; Holý, V.

doi:10.1107/s1600577517009584

Cited by 9 publications

(11 citation statements)

References 30 publications

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“…As the extended Poincaré plot assesses autocorrelation in a time-series, a higher degree of autocorrelation suggests the presence of an autoregressive process. An in-depth analysis can provide us more information about the order of such a process (Ramsey, 1974). In a first order autoregressive process [AR(1)], the current value of the process is based on the immediately preceding value, and we expect to observe the following behavior:…”

Section: Discussionmentioning

confidence: 99%

The Application of the Extended Poincaré Plot in the Analysis of Physiological Variabilities

et al. 2019

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The Poincaré plot is a geometrical technique used to visualize and quantify the correlation between two consecutive data points in a time-series. Since the dynamics of fluctuations in physiological rhythms exhibit long-term correlation and memory, this study aimed to extend the Poincaré plot by calculating the correlation between sequential data points in a time-series, rather than between two consecutive points. By incorporating this so-called lag, we hope to integrate a temporal aspect into quantifying the correlation, to depict whether a physiological system holds prolonged association between events separated by time. In doing so, it attempts to instantaneously characterize the intrinsic behavior of a complex system. We tested this hypothesis on three different physiological time-series: heart rate variability in patients with liver cirrhosis, respiratory rhythm in asthma and body temperature fluctuation in patients with cirrhosis, to evaluate the potential application of the extended Poincaré method in clinical practice. When studying the cardiac inter-beat intervals, the extended Poincaré plot revealed a stronger autocorrelation for patients with decompensated liver cirrhosis compared to less severe cases using Pearson’s correlation coefficient. In addition, long-term variability (known as SD2 in the extended Poincaré plot) appeared as an independent prognostic variable. This holds significance by acting as a non-invasive tool to evaluate patients with chronic liver disease and potentially facilitate transplant selection as an adjuvant to traditional criteria. For asthmatics, employing the extended Poincaré plot allowed for a non-invasive tool to differentially diagnose various classifications of respiratory disease. In the respiratory inter-breath interval analysis, the receiver operating characteristic (ROC) curve provided evidence that the extension of the Poincaré plot holds a greater advantage in the classification of asthmatic patients, over the traditional Poincaré plot. Lastly, the analysis of body temperature from patients using the extended Poincaré plot helped identify inpatients from outpatients with cirrhosis. Through these analyses, the extended Poincaré plot provided unique and additional information which could potentially make a difference in clinical practice. Conclusively, the potential use of our work lies in its possible application of predicting mortality for the organ allocation procedure in patients with cirrhosis and non-invasively distinguish between atopic and non-atopic asthma.

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Section: Discussionmentioning

confidence: 99%

The Application of the Extended Poincaré Plot in the Analysis of Physiological Variabilities

et al. 2019

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“…X-rays have a long penetration depth compared with electron and optical beams [1], and modern X-ray optics can provide nanofocusing at the range of tens of nanometers [2,3]. This development has made it possible to investigate complete single semiconductor nanostructures [4][5][6][7][8][9][10][11]. By combining the nanofocused X-ray probe with an applied electrical bias as well as electrical current detection, nanodevices can be investigated in more or less realistic operational conditions.…”

Section: Introductionmentioning

confidence: 99%

Combining Nanofocused X-Rays with Electrical Measurements at the NanoMAX Beamline

et al. 2019

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The advent of nanofocused X-ray beams has allowed the study of single nanocrystals and complete nanoscale devices in a nondestructive manner, using techniques such as scanning transmission X-ray microscopy (STXM), X-ray fluorescence (XRF) and X-ray diffraction (XRD). Further insight into semiconductor devices can be achieved by combining these techniques with simultaneous electrical measurements. Here, we present a system for electrical biasing and current measurement of single nanostructure devices, which has been developed for the NanoMAX beamline at the fourth-generation synchrotron, MAX IV, Sweden. The system was tested on single InP nanowire devices. The mechanical stability was sufficient to collect scanning XRD and XRF maps with a 50 nm diameter focus. The dark noise of the current measurement system was about 3 fA, which allowed fly scan measurements of X-ray beam induced current (XBIC) in single nanowire devices.

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“…This latter property, combined with the fact that X-ray diffraction is one of the most precise techniques for studying the state of strain in such small objects, led us to study the diffraction from twisted monocrystalline nanowires within the framework of the kinematic theory of diffraction by helices. Furthermore, as it is now possible, using X-rays and since the advent of thirdgeneration synchrotron sources, to study single nanowires (Favre-Nicolin et al, 2010;Labat et al, 2015;Davtyan et al, 2017), this publication is focused on diffraction from a single object.…”

Section: Introductionmentioning

confidence: 99%

Diffraction from twisted nanowires: helicity revealed by anisotropy

Gailhanou

Roussel

2018

J Appl Cryst

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The helical nature of twisted nanowires is studied by simulated X‐ray diffraction. It is shown that this helicity is revealed by the anisotropy, which can be both an elastic anisotropy, through the warping displacement generated by torsion, or a shape anisotropy of the cross section. To support the analytical calculations, based on the kinematic theory of diffraction by helices, atomistic simulations of copper nanowires are performed.

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Characterization of individual stacking faults in a wurtzite GaAs nanowire by nanobeam X-ray diffraction

Cited by 9 publications

References 30 publications

The Application of the Extended Poincaré Plot in the Analysis of Physiological Variabilities

The Application of the Extended Poincaré Plot in the Analysis of Physiological Variabilities

Combining Nanofocused X-Rays with Electrical Measurements at the NanoMAX Beamline

Diffraction from twisted nanowires: helicity revealed by anisotropy

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