186 research outputs found
Magnetic properties of epitaxial FeO films with various crystal orientations and TMR effect in room temperature
FeO is a ferrimagnetic spinel ferrite that exhibits electric
conductivity at room temperature (RT). Although the material has been predicted
to be a half metal according to ab-initio calculations, magnetic tunnel
junctions (MTJs) with FeO electrodes have demonstrated a small tunnel
magnetoresistance effect. Not even the sign of the TMR ratio has been
experimentally established. Here, we report on the magnetic properties of
epitaxial FeO films with various crystal orientations. The films
exhibited apparent crystal orientation dependence on hysteresis curves. In
particular, FeO(110) films exhibited in-plane uniaxial magnetic
anisotropy. With respect to the squareness of hysteresis, FeO (111)
demonstrated the largest squareness. Furthermore, we fabricated MTJs with
FeO(110) electrodes, and obtained an TMR effect of -12\% at RT. The
negative TMR ratio corresponded to the negative spin polarization of
FeO predicted from band calculations
Random phase-free kinoform for large objects
We propose a random phase-free kinoform for large objects. When not using the
random phase in kinoform calculation, the reconstructed images from the
kinoform are heavy degraded, like edge-only preserved images. In addition, the
kinoform cannot record an entire object that exceeds the kinoform size because
the object light does not widely spread. In order to avoid this degradation and
to widely spread the object light, the random phase is applied to the kinoform
calculation; however, the reconstructed image is contaminated by speckle noise.
In this paper, we overcome this problem by using our random phase-free method
and error diffusion method
A reservoir trap for antiprotons
We have developed techniques to extract arbitrary fractions of antiprotons
from an accumulated reservoir, and to inject them into a Penning-trap system
for high-precision measurements. In our trap-system antiproton storage times >
1.08 years are estimated. The device is fail-safe against power-cuts of up to
10 hours. This makes our planned comparisons of the fundamental properties of
protons and antiprotons independent from accelerator cycles, and will enable us
to perform experiments during long accelerator shutdown periods when background
magnetic noise is low. The demonstrated scheme has the potential to be applied
in many other precision Penning trap experiments dealing with exotic particles.Comment: Article by the BASE-collaboration at CERN. Results from the
Antiproton physics run 2014. Submitted to International Journal of Mass
Spectrometry, 8th of April 201
The first total synthesis of bufobutanoic acid by two routes based on nucleophilic substitution reaction on indole nucleus
金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部Regioselective nucleophilic substitution reaction of 1- hydroxytryptamines led to establish two novel routes for the first synthesis of bufobutanoic acid. An effective synthesis of 5-benzyloxytryptamine from tryptamine is also reported
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