Comparison of Experimental STEM Conditions for Fluctuation Electron Microscopy

Abstract

Abstract

Focused Ion Beam Sample Preparation for In Situ Thermal and Electrical Transmission Electron Microscopy

“…An initially crystalline silicon layer, which was grown on the top of a silicon on insulator wafer by molecular beam epitaxy, is amorphized by silicon ion implantation at the Helmholtz-Zentrum Dresden-Rossendorf. More information about this material can be found in Radić et al (2020). For the demonstration of the sample's quality we use a single-crystalline NiAl specimen.…”

Estimating illumination coherence width from focused-probe intensity profiles

“…Illumination spatial coherence can be controlled by adjusting the pre-specimen optics [2,3]. High spatial coherence generally results in low illumination fluence, and the scattered signals can be noisy.…”

“…By concentrating our fitting function on the higher-order rings, along with a fitted zero-offset, we were able to obtain the fits shown in Figure 2a for two different probes. At large values of x=qr, the peaks in the ideal Airy intensity function should follow |J1(x)/x| 2 1/x 3 . Figure 2b shows the same data multiplied by x 3 =(qr) 3 .…”

“…At large values of x=qr, the peaks in the ideal Airy intensity function should follow |J1(x)/x| 2 1/x 3 . Figure 2b shows the same data multiplied by x 3 =(qr) 3 . Interpreting the discrepancy from the ideal probe as coming entirely from spatial incoherence, we infer that the spatial coherence angular widths relative to the aperture radii were 0.8 and 0.21 for probes 1 and 2, respectively.…”

“…FEM uses low-resolution probestypically 1.0 nm and biggerwhich should be diffraction-limited. Nevertheless, a more accurate methodology may need to include wavefront aberrations, such as defocus, spherical aberration and astigmatism [3]. It has been pointed out that defocus can be an important issue [3], even for diffractionlimited probes.…”