59 research outputs found
ΠΠ»ΠΈΡΠ½ΠΈΠ΅ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ Π²ΡΡΠΎΠΊΠΎΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΡΠΌ ΠΏΠΎΡΠΎΠΊΠΎΠΌ ΠΈΠΎΠ½ΠΎΠ² Zr Π½Π° ΡΡΡΡΠΊΡΡΡΡ ΠΈ ΠΌΠ΅Ρ Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° Π²ΡΡΠΎΠΊΠΎΠΏΡΠΎΡΠ½ΠΎΠΉ ΡΡΠ°Π»ΠΈ 30Π₯ΠΠ‘Π2Π
ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΡΡΡΠΊΡΡΡΡ ΠΌΠΎΠ΄ΠΈΡΠΈΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ Π²ΡΡΠΎΠΊΠΎΠΏΡΠΎΡΠ½ΠΎΠΉ ΡΡΠ°Π»ΠΈ30Π₯ΠΠ‘Π2Π ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΡΠΎΡΠ²Π΅ΡΠΈΠ²Π°ΡΡΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ, Π° ΡΠ°ΠΊ ΠΆΠ΅ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΡΠ΅Π½ΡΠ³Π΅Π½ΠΎΠ²ΡΠΊΠΎΠΉ Π΄ΠΈΡΡΠ°ΠΊΡΠΈΠΈ. ΠΡΠΏΡΡΠ°Π½ΠΈΡ Π½Π° ΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΈ ΡΠΈΠΊΠ»ΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΠ΅ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈΠ΄Π»Ρ ΡΡΠ°Π»ΡΠ½ΡΡ
ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² Π² ΡΠΎΡΡΠΎΡΠ½ΠΈΠΈ ΠΏΠΎΡΡΠ°Π²ΠΊΠΈ, Π° ΡΠ°ΠΊ ΠΆΠ΅ ΠΏΠΎΡΠ»Π΅ ΠΌΠΎΠ΄ΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡΠΏΠΎΡΠΎΠΊΠΎΠΌ ΠΈΠΎΠ½ΠΎΠ² Zr
Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading
Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications
Structural levels of deformation and failure of heat-resistant 12Cr1MoV steel modified by vacuum arc treatment by Zr{+} ion beam
Study of structural changes occurring in the surface layer modified by ion-beam irradiation was carried out by means of optical, scanning and transmission electron microscopy. It was shown that irradiation induces the structure modification not only in the surface layer, but along the entire cross section of 1 mm thick specimens. It was elucidated that the complex pattern of structural changes is responsible for the pronounced variation of mechanical properties taking place under static tension and cyclic alternating bending
Sputtered NbN Films for Ultrahigh Performance Superconducting Nanowire Single-Photon Detectors
Nowadays ultrahigh performance superconducting nanowire single-photon
detectors are the key elements in a variety of devices from biological research
to quantum communications and computing. Accurate tuning of superconducting
material properties is a powerful resource for fabricating single-photon
detectors with a desired properties. Here, we report on the major theoretical
relations between ultrathin niobium nitride (NbN) films properties and
superconducting nanowire single-photon detectors characteristics, as well as
ultrathin NbN films properties dependence on reactive magnetron sputtering
recipes. Based on this study we formulate the exact requirements to ultrathin
NbN films for ultrahigh performance superconducting nanowire single-photon
detectors. Then, we experimentally study ultrathin NbN films properties
(morphology, crystalline structure, critical temperature, sheet resistance) on
silicon, sapphire, silicon dioxide and silicon nitride substrates sputtered
with various recipes. We demonstrate ultrathin NbN films (obtained with more
than 100 films deposition) with a wide range of critical temperature from 2.5
to 12.1 K and sheet resistance from 285 to 2000 ~/sq, as well as
investigate a sheet resistance evolution over for more than 40\% within two
years. Finally, we found out that one should use ultrathin NbN films with
specific critical temperature near 9 K and sheet resistance of 400 ~/sq
for ultrahigh performance SNSPD.Comment: The following article has been submitted to APL Materials. After it
is published, it will be found at https://pubs.aip.org/aip/apm. Copyright
2023 Author(s). This article is distributed under a Creative Commons
Attribution (CC BY) Licens
Origin of exchange bias in [Co/Pt]ML/Fe multilayer with orthogonal magnetic anisotropies
Magnetization reversal of soft ferromagnetic Fe layer, coupled to [Co/Pt]ML
multilayer [ML] with perpendicular magnetic anisotropy (PMA), has been studied
in-situ with an aim to understand the origin of exchange bias (EB) in
orthogonal magnetic anisotropic systems. The interface remanant state of the ML
is modified by magnetic field annealing, and the effect of the same on the soft
Fe layer is monitored using the in-situ magneto-optical Kerr effect (MOKE). A
considerable shift in the Fe layer hysteresis loop from the centre and an
unusual increase in the coercivity, similar to exchange bias phenomena, is
attributed to the exchange coupling at the [Co/Pt]ML and Fe interface. The
effect of the coupling on spin orientation at the interface is further explored
precisely by performing an isotope selective grazing incident nuclear resonance
scattering (GINRS) technique. Here, the interface selectivity is achieved by
introducing a 2 nm thick Fe57 marker between [Co/Pt]ML and Fe layers. Interface
sensitivity is further enhanced by performing measurements under the x-ray
standing wave conditions. The combined MOKE and GINRS analysis revealed the
unidirectional pinning of the Fe layer due to the net in-plane magnetic spin at
the interface caused by magnetic field annealing. Unidirectional exchange
coupling or pinning at the interface, which may be due to the formation of
asymmetrical closure domains, is found responsible for the origin of EB with an
unusual increase in coercivity.Comment: 9 figures, 1 tabl
Rocking curve measurements revisited
The study of materials by diffraction methods started about 100 years ago with the pioneering experiment of Laue, Friedrich and Knipping, when the first X-ray diffraction patterns of single crystals were obtained (Friedrich et al., 1912). This was the beginning of a rapid development fostering many diffraction-based methods and techniques, which is still continuing. The measurement of rocking curves and the associated derived quantitative parameters, such as the βfull width at half-maximumβ (FWHM) of the curves, has been performed since at least 1921 (Davis & Stempel, 1921) by exploiting the X-ray diffraction (XRD) properties of crystals. Since then, this has become one of the most powerful methods for the diffraction-based characterization of crystalline materials. The experimentally closely related method of X-ray diffraction imaging or X-ray diffraction topography has been used since about 1931 (Berg, 1931). Soon after World War II, the requirements of the electronics industry for the nondestructive analysis of defects in semiconductor materials like silicon and germanium (and others) boosted the improvement of these methods to their modern high-resolution variants like high-resolution X-ray diffraction and in particular high-resolution and high strain sensitivity X-ray topography (Bond & Andrus, 1952; Lang, 1957). This evolution was additionally accelerated in the late 1970s by the use of synchrotrons as dedicated X-ray sources and later on, starting in the 1990s, by the use of third-generation synchrotron sources...
Magnetic Dirac semimetal state of (Mn,Ge)BiTe
For quantum electronics, the possibility to finely tune the properties of
magnetic topological insulators (TIs) is a key issue. We studied solid
solutions between two isostructural Z TIs, magnetic MnBiTe and
nonmagnetic GeBiTe, with Z invariants of 1;000 and 1;001,
respectively. For high-quality, large mixed crystals of
GeMnBiTe, we observed linear x-dependent magnetic
properties, composition-independent pairwise exchange interactions along with
an easy magnetization axis. The bulk band gap gradually decreases to zero for
from 0 to 0.4, before reopening for , evidencing topological phase
transitions (TPTs) between topologically nontrivial phases and the semimetal
state. The TPTs are driven purely by the variation of orbital contributions. By
tracing the x-dependent contribution to the states near the fundamental
gap, the effective spin-orbit coupling variation is extracted. As varies,
the maximum of this contribution switches from the valence to the conduction
band, thereby driving two TPTs. The gapless state observed at closely
resembles a Dirac semimetal above the Neel temperature and shows a magnetic gap
below, which is clearly visible in raw photoemission data. The observed
behavior of the GeMnBiTe system thereby demonstrates an
ability to precisely control topological and magnetic properties of TIs
ΠΡΡΠΎΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π°ΡΠΏΠ΅ΠΊΡΡ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° Π΄ΠΈΠ°Π³ΡΠ°ΠΌΠΌ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΈΡ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ²
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Energetic particle influence on the Earth's atmosphere
This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally
galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere
are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earthβs atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere
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