114 research outputs found
Fabrication of FeSi and Fe3Si compounds by electron beam induced mixing of [Fe/Si]2 and [Fe3/Si]2 multilayers grown by focused electron beam induced deposition
Fe-Si binary compounds have been fabricated by focused electron beam induced
deposition by the alternating use of iron pentacarbonyl, Fe(CO)5, and
neopentasilane, Si5H12 as precursor gases. The fabrication procedure consisted
in preparing multilayer structures which were treated by low-energy electron
irradiation and annealing to induce atomic species intermixing. In this way we
are able to fabricate FeSi and Fe3Si binary compounds from [Fe=Si]2 and
[Fe3=Si]2 multilayers, as shown by transmission electron microscopy
investigations. This fabrication procedure is useful to obtain nanostructured
binary alloys from precursors which compete for adsorption sites during growth
and, therefore, cannot be used simultaneously
Alignment of electron optical beam shaping elements using a convolutional neural network
A convolutional neural network is used to align an orbital angular momentum sorter in a transmission electron microscope. The method is demonstrated using simulations and experiments. As a result of its accuracy and speed, it offers the possibility of real-time tuning of other electron optical devices and electron beam shaping configurations
Image charge screening: a new approach to enhance magnetic ordering temperatures
We have tested the concept of image charge screening as a new approach to
enhance magnetic ordering temperatures and superexchange interactions in ultra
thin films. Using a 3 monolayer NiO(100) film grown on Ag(100) and an
identically thin film on MgO(100) as model systems, we observed that the Neel
temperature of the NiO film on the highly polarizable metal substrate is 390 K
while that of the film on the poorly polarizable insulator substrate is below
40 K. This demonstrates that screening by highly polarizable media may point to
a practical way towards designing strongly correlated oxide nanostructures with
greatly improved magnetic properties.Comment: 5 pages, 4 figure
X-RAY-EMISSION MODULATION BY ELECTRON CHANNELING AND SITE OCCUPANCY IN GARNETS
Axial channelling effects in a pyrope garnet for three zone axis orientations: [111], [211], and [311] have been investigated. The variations of the characteristic X-ray emission under the [111] zone axis diffracting conditions was correlated with dynamical n-beam calculations. Site occupancies determinations obtained by comparing X + Z and Y sites have been made using ALCHEMI techniques
Method for determination of the displacement field in patterned nanostructures by TEM/CBED analysis of split high-order Laue zone line profiles
A method to extract accurate information on the displacement field distribution from split high-order Laue zones lines in a convergent-beam electron diffraction pattern of nanostructures has been developed. Starting from two-dimensional many beam dynamical simulation of HOLZ patterns, we assembled a recursive procedure to reconstruct the displacement field in the investigated regions of the sample, based on the best fit of a parametrized model. This recursive procedure minimizes the differences between simulated and experimental patterns, taken in strained regions, by comparing the corresponding rocking curves of a number of high-order Laue zone reflections. Due to its sensitivity to small displacement variations along the electron beam direction, this method is able to discriminate between different models, and can be also used to map a strain field component in the specimen. We tested this method in a series of experimental convergent-beam electron diffrac tion patterns, taken in a shallow trench isolation structure. The method presented here is of general validity and, in principle, it can be applied to any sample where not negligible strain gradients along the beam direction are present
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