Observation of Magnetic Induction Distribution   by Scanning Interference Electron Microscopy

Takahashi, Yoshio; Yajima, Yoshiyuki; Kuroda, Katsuhiro

doi:10.1143/jjap.33.l1352

Cited by 17 publications

(5 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this manuscript, we demonstrate a method to measure specimen-induced electron phase shifts measured from the interference of multiple STEM probe beams produced with an electron diffraction grating. Between 1989 and 1994, several groups proposed or demonstrated early forms of STEM holography (STEMH) using an electron biprism to produce two beams [23][24][25]; because the speed of pixelated detectors was insufficient at the time, these first demonstrations employed a grating mask to map fringe shifts into a single intensity signal per probe position. Our implementation of the technique is different than these early approaches, but as the basic principle matches these works, we retain the same name.…”

Section: T(x)mentioning

confidence: 99%

Interpretable and Efficient Interferometric Contrast in Scanning Transmission Electron Microscopy with a Diffraction-Grating Beam Splitter

et al. 2018

View full text Add to dashboard Cite

Efficient imaging of biomolecules, 2D materials and electromagnetic fields depends on retrieval of the phase of transmitted electrons. We demonstrate a method to measure phase in a scanning transmission electron microscope using a nanofabricated diffraction grating to produce multiple probe beams. The measured phase is more interpretable than phase-contrast scanning transmission electron microscopy techniques without an off-axis reference wave, and the resolution could surpass that of off-axis electron holography. We apply the technique to image nanoparticles, carbon substrates and electric fields. The contrast observed in experiments agrees well with contrast predicted in simulations.

show abstract

Section: T(x)mentioning

confidence: 99%

Interpretable and Efficient Interferometric Contrast in Scanning Transmission Electron Microscopy with a Diffraction-Grating Beam Splitter

et al. 2018

View full text Add to dashboard Cite

show abstract

“…This separation is sufficient to study nano-materials using classic interferometric techniques. Such a technique within an electron microscope was initially theorized and explored experimentally in the late 1980s and early 1990s [36][37][38]. The initial experimental attempts proved too challenging for various reasons, and so the technique was ultimately abandoned, although Cowley expanded the theory in 2003 [39].…”

Section: Introductionmentioning

confidence: 99%

Path-separated electron interferometry in a scanning transmission electron microscope

Yasin¹,

Harvey²,

Chess³

et al. 2018

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

We report a path-separated electron interferometer within a scanning transmission electron microscope. In this setup, we use a nanofabricated grating as an amplitude-division beamsplitter to prepare multiple spatially separated, coherent electron probe beams. We achieve path separations of 30 nm. We pass the +1 diffraction order probe through amorphous carbon while passing the 0th and −1 orders through vacuum. The probes are then made to interfere via imaging optics, and we observe an interference pattern at the CCD detector with up to 39.7% fringe visibility. We show preliminary experimental results in which the interference pattern was recorded during a 1D scan of the diffracted probes across a test phase object. These results qualitatively agree with a modeled interference predicted by an independent measurement of the specimen thickness. This experimental design can potentially be applied to phase contrast imaging and fundamental physics experiments, such as an exploration of electron wave packet coherence length.

show abstract

“…Several decades ago, an interferometric technique called STEM holography (STEMH) was initially developed as a phase contrast electron imaging technique. − These arrangements used a charged biprism wire to split an electron beam into two probes focused at the specimen. With one beam transmitted through the specimen, the interference between the two was recorded.…”

Section: Experimental Setupmentioning

confidence: 99%

Probing Light Atoms at Subnanometer Resolution: Realization of Scanning Transmission Electron Microscope Holography

et al. 2018

View full text Add to dashboard Cite

Atomic resolution imaging in transmission electron microscopy (TEM) and scanning TEM (STEM) of light elements in electron-transparent materials has long been a challenge. Biomolecular materials, for example, are rapidly altered when illuminated with electrons. These issues have driven the development of TEM and STEM techniques that enable the structural analysis of electron beam-sensitive and weakly scattering nano-materials. Here, we demonstrate such a technique, STEM holography, capable of absolute phase and amplitude object wave measurement with respect to a vacuum reference wave. We use an amplitude-dividing nanofabricated grating to prepare multiple spatially separated electron diffraction probe beams focused at the sample plane, such that one beam transmits through the specimen while the others pass through vacuum. We raster-scan the diffracted probes over the region of interest. We configure the post-specimen imaging system of the microscope to diffraction mode, overlapping the probes to form an interference pattern at the detector. Using a fast-readout, direct electron detector, we record and analyze the interference fringes at each position in a 2D raster scan to reconstruct the complex transfer function of the specimen, t(x). We apply this technique to image a standard target specimen consisting of gold nanoparticles on a thin amorphous carbon substrate, and demonstrate 2.4Å resolution phase images. We find that STEM holography offers higher phase-contrast of the amorphous material while maintaining Au atomic lattice resolution when compared with high angle annular dark field STEM.

show abstract

Observation of Magnetic Induction Distribution by Scanning Interference Electron Microscopy

Cited by 17 publications

References 11 publications

Interpretable and Efficient Interferometric Contrast in Scanning Transmission Electron Microscopy with a Diffraction-Grating Beam Splitter

Interpretable and Efficient Interferometric Contrast in Scanning Transmission Electron Microscopy with a Diffraction-Grating Beam Splitter

Path-separated electron interferometry in a scanning transmission electron microscope

Probing Light Atoms at Subnanometer Resolution: Realization of Scanning Transmission Electron Microscope Holography

Contact Info

Product

Resources

About