733 research outputs found
Optical spectroscopy of rare-earth ions doped KY(WO4)2 thin films
KY(WO4)2 thin films doped with Dy3+, Tb3+, Yb3+, were grown onto KY(WO4)2 substrates using liquid-phase epitaxy. Spectroscopic investigations of the grown layers were performed. Obtained results were compared with spectra given for bulk crystals. Upconversion experiments after direct Yb3+ excitation in Dy3+-Yb3+ and Tb3+-Yb3+ codoped layers will be also presented
Resolution in Focused Electron- and Ion-Beam Induced Chemical Vapor Deposition
The key physical processes governing resolution of focused electron-beam and
ion-beam-assisted chemical vapor deposition are analyzed via an adsorption rate
model. We quantify for the first time how the balance of molecule depletion and
replenishment determines the resolution inside the locally irradiated area.
Scaling laws are derived relating the resolution of the deposits to molecule
dissociation, surface diffusion, adsorption, and desorption. Supporting results
from deposition experiments with a copper metalorganic precursor gas on a
silicon substrate are presented and discussed.Comment: 4 pages, 4 figures, 1 tabl
Nano-Hall sensors with granular Co-C
We analyzed the performance of Hall sensors with different Co-C ratios,
deposited directly in nano-structured form, using gas molecules,
by focused electron or ion beam induced deposition. Due to the enhanced
inter-grain scattering in these granular wires, the Extraordinary Hall Effect
can be increased by two orders of magnitude with respect to pure Co, up to a
current sensitivity of . We show that the best magnetic field
resolution at room temperature is obtained for Co ratios between 60% and 70%
and is better than . For an active area of the sensor of , the room temperature magnetic flux resolution is , in the thermal noise frequency range, i.e. above 100
kHz.Comment: 5 pages, 4 figure
Early Classifying Multimodal Sequences
Often pieces of information are received sequentially over time. When did one
collect enough such pieces to classify? Trading wait time for decision
certainty leads to early classification problems that have recently gained
attention as a means of adapting classification to more dynamic environments.
However, so far results have been limited to unimodal sequences. In this pilot
study, we expand into early classifying multimodal sequences by combining
existing methods. We show our new method yields experimental AUC advantages of
up to 8.7%.Comment: 7 pages, 5 figure
A novel copper precursor for electron beam induced deposition
A fluorine free copper precursor, Cu(tbaoac)2 with the chemical sum formula CuC16O6H26 is introduced for focused electron beam induced deposition (FEBID). FEBID with 15 keV and 7 nA results in deposits with an atomic composition of Cu:O:C of approximately 1:1:2. Transmission electron microscopy proved that pure copper nanocrystals with sizes of up to around 15 nm were dispersed inside the carbonaceous matrix. Raman investigations revealed a high degree of amorphization of the carbonaceous matrix and showed hints for partial copper oxidation taking place selectively on the surfaces of the deposits. Optical transmission/reflection measurements of deposited pads showed a dielectric behavior of the material in the optical spectral range. The general behavior of the permittivity could be described by applying the Maxwell–Garnett mixing model to amorphous carbon and copper. The dielectric function measured from deposited pads was used to simulate the optical response of tip arrays fabricated out of the same precursor and showed good agreement with measurements. This paves the way for future plasmonic applications with copper-FEBID
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