78 research outputs found
Electrical Resistivity Peculiarities of the Nanograined Bi2Te3 Material
The hot quasiisostaic pressure method was applied to sinter the nanograined Bi2Te3 material. The
samples with various mean grain size of 64, 61, 56 and 51 nm were prepared by changing the pressure of
sintering. It was found that the specific electrical resistivity of the material under study increases when
the mean grain size decreases. The Hall effect was measured to extract the concentration and mobility
values of the charge carries. It was found that the electron concentration decreases as the mean grain size
decreases while the electron mobility has extreme dependence on the grain size
Characterization of Bulk Nanostructural Bi2Te3-based Material Prepared by Microwave-solvothermal Synthesis and Hot Isostatic Pressure
The bulk nanostructural Bi2Te3-based material was prepared by microwave assisted solvothermal
method and hot isostatic pressure. Optimal synthesis conditions of the Bi2Te3 nanopowder were found. It
was established that hot isostatic pressing of the nanopowders at the temperature of 400 Π‘ and the pres-sures of 2, 4, 6 and 8 GPa allowed us to prepare the homogeneous and dense Bi2Te3-based material with
the mean grain size of~50 nm. It is found that an electrical resistivity increases as the mean grain size of
the material under study decreases.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3638
Linear Positive Magnetoresistivity of the Bi1.9Lu0.1Te3 Alloy with Inhomogeneous Micrograined Structure
Positive nonsaturating transverse magnetoresistivity (MR) has been observed below room temperature in the Bi1.9Lu0.1Te3 alloy with inhomogeneous micrograined structure. A crossover from parabolic MR ~ B2 dependence in low magnetic fields to linear MR ~ B dependence in high fields was found in the magnetoresistivity curves. The crossover field is shifted to lower magnetic fields as temperature decreases. Within the temperature range of βmetalβ type of conductivity, the temperature dependences of the specific electrical resistivity and MR magnitude are determined by the temperature dependence of the carrier mobility due to acoustic phonon scattering. Linear MR can be associated with microstructural inhomogeneity leading to strong electrical disorder of the Bi1.9Lu0.1Te3
Electrical Resistivity Peculiarities of the Nanograined Bi2Te3 Material
The hot quasiisostaic pressure method was applied to sinter the nanograined Bi2Te3 material. The
samples with various mean grain size of 64, 61, 56 and 51 nm were prepared by changing the pressure of
sintering. It was found that the specific electrical resistivity of the material under study increases when
the mean grain size decreases. The Hall effect was measured to extract the concentration and mobility
values of the charge carries. It was found that the electron concentration decreases as the mean grain size
decreases while the electron mobility has extreme dependence on the grain size
Hopping Conductivity and Negative Magnetoresistance of the Bulk Nanograined Bi2Te3 Material
The bulk nanograined Bi2Te3 material was prepared by the microwave assisted solvothermal method
and cold isostatic pressure method. It was found that above T* β 190 K the temperature dependence of the
specific electrical resistivity of material is of metallic type, while below this temperature a semiconductor
conductivity takes place. Within the temperature ΞT β 90 K-35 K interval the electrical conductivity of material
can be described by the variable-range hopping conductivity mechanism. Negative magnetoresistance
was observed at the same temperature interval
Plasma focus installation as a tool for the study of the interaction of high power plasma streams with condensed matter
In this work the possibilities of the use of the high-current discharges of Plasma Focus type for the investigation of
the effect of plasma on the materials are discussed. From this point of view the properties of plasma streams and ion
beams arising in the PF discharges are studied. Here, as an example of an application of the Plasma Focus device (PF),
we studied the influence on Vanadium (perspective material in nuclear power engineering) a cumulative streams
producing in the P
Unconventional ferromagnetism and transport properties of (In,Mn)Sb dilute magnetic semiconductor
Narrow-gap higher mobility semiconducting alloys In_{1-x}Mn_{x}Sb were
synthesized in polycrystalline form and their magnetic and transport properties
have been investigated. Ferromagnetic response in In_{0.98}Mn_{0.02}Sb was
detected by the observation of clear hysteresis loops up to room temperature in
direct magnetization measurements. An unconventional (reentrant) magnetization
versus temperature behavior has been found. We explained the observed
peculiarities within the frameworks of recent models which suggest that a
strong temperature dependence of the carrier density is a crucial parameter
determining carrier-mediated ferromagnetism of (III,Mn)V semiconductors. The
correlation between magnetic states and transport properties of the sample has
been discussed. The contact spectroscopy method is used to investigate a band
structure of (InMn)Sb near the Fermi level. Measurements of the degree of
charge current spin polarization have been carried out using the point contact
Andreev reflection (AR) spectroscopy. The AR data are analyzed by introducing a
quasiparticle spectrum broadening, which is likely to be related to magnetic
scattering in the contact. The AR spectroscopy data argued that at low
temperature the sample is decomposed on metallic ferromagnetic clusters with
relatively high spin polarization of charge carriers (up to 65% at 4.2K) within
a cluster.Comment: 19 pages, 9 figures, 1 tabl
Universal hierarchical symmetry for turbulence and general multi-scale fluctuation systems
A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic
The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world
Π’ΡΠ½Π½Π΅Π»ΡΠ½Π°Ρ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΡ ΡΠ²Π΅ΡΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΡΡΠ΅Π³ΠΎ ΠΈΠ½Π΄ΠΈΡ Π² ΠΏΠΎΡΠΈΡΡΠΎΠΌ ΡΡΠ΅ΠΊΠ»Π΅
ΠΠ»Π΅ΠΊΡΡΠΈΡΠ½ΠΈΠΉ ΠΎΠΏΡΡ ΡΠ½Π΄ΡΡ ΡΠ½Π΄ΡΡ Π² ΠΏΠΎΡΠΈΡΡΠΎΠΌΡ ΡΠΊΠ»Ρ Π· ΡΠΎΠ·ΠΌΡΡΠΎΠΌ ΠΏΠΎΡ 7 Π½ΠΌ Π±ΡΠ»ΠΎ Π²ΠΈΠ²ΡΠ΅Π½ΠΎ Π² ΡΠ½ΡΠ΅ΡΠ²Π°Π»Ρ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ 2,3-300 K. ΠΠΈΡΠ²Π»Π΅Π½ΠΎ, ΡΠΎ Π΄ΠΎΡΠ»ΡΠ΄ΠΆΡΠ²Π°Π½ΠΈΠΉ ΠΌΠ°ΡΠ΅ΡΡΠ°Π» Π·Π°Π·Π½Π°Ρ ΠΏΠ΅ΡΠ΅Ρ
ΡΠ΄ Π² Π½Π°Π΄ΠΏΡΠΎΠ²ΡΠ΄Π½ΠΈΠΉ ΡΡΠ°Π½ ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ TC = 3,9 K. Π ΡΠ·ΠΊΠΈΠΉ Π°ΡΠΈΠΌΠ΅ΡΡΠΈΡΠ½ΠΈΠΉ ΠΏΡΠΊ Π½Π° ΠΊΡΠΈΠ²ΡΠΉ R(T) Π²ΠΈΡΠ²Π»Π΅Π½ΠΈΠΉ ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ 6,4 K. ΠΠΏΠ΅ΡΡΠ΅ R(T) Π·Π°Π»Π΅ΠΆΠ½ΡΡΡΡ ΠΏΡΠΎΠ°Π½Π°Π»ΡΠ·ΠΎΠ²Π°Π½Π° Π΄Π»Ρ Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΠΎΡ ΡΠ°Π·ΠΈ. ΠΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΠΎ Π² ΡΠ½ΡΠ΅ΡΠ²Π°Π»Ρ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ
15-80 K ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½Π° Π·Π°Π»Π΅ΠΆΠ½ΡΡΡΡ ΠΎΠΏΠΎΡΡ ΠΎΠΏΠΈΡΡΡΡΡΡΡ ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌΠΎΠΌ ΡΡΠ½Π΅Π»ΡΠ²Π°Π½Π½Ρ Π½ΠΎΡΡΡΠ² Π·Π°ΡΡΠ΄Ρ Π² ΡΠ°ΠΌΠΊΠ°Ρ
ΠΌΠΎΠ΄Π΅Π»Ρ Π¨Π΅Π½Π³Π°. ΠΠΎΡΠ»ΡΠ΄ΠΆΡΠ²Π°Π½ΠΈΠΉ ΠΌΠ°ΡΠ΅ΡΡΠ°Π» ΠΌΠΎΠΆΠ½Π° ΡΠΎΠ·Π³Π»ΡΠ΄Π°ΡΠΈ ΡΠΊ Π΅Π»Π΅ΠΊΡΡΠΈΡΠ½ΠΎ Π½Π΅ΠΎΠ΄Π½ΠΎΡΡΠ΄Π½ΠΈΠΉ ΠΌΠ°ΡΠ΅ΡΡΠ°Π», Π²
ΡΠΊΠΎΠΌΡ ΠΌΠ΅ΡΠ°Π»Π΅Π²Ρ ΠΎΠ±Π»Π°ΡΡΡ Π² ΠΏΠΎΡΠ°Ρ
ΠΊΠΎΠ½ΡΠ°ΠΊΡΡΡΡΡ ΠΌΡΠΆ ΡΠΎΠ±ΠΎΡ Π·Π° Π΄ΠΎΠΏΠΎΠΌΠΎΠ³ΠΎΡ Π΄ΡΠ΅Π»Π΅ΠΊΡΡΠΈΡΠ½ΠΈΡ
ΠΌΡΡΡΠΊΠΎΠΌ ΠΌΠ°ΡΡΠΈΡΡ
Π·Ρ ΡΠΊΠ»Π°. ΠΠ΅ΡΠ΅Π½Π΅ΡΠ΅Π½Π½Ρ Π·Π°ΡΡΠ΄Ρ ΠΌΡΠΆ ΠΌΠ΅ΡΠ°Π»Π΅Π²ΠΈΠΌΠΈ ΠΎΠ±Π»Π°ΡΡΡΠΌΠΈ Π²ΡΠ΄Π±ΡΠ²Π°ΡΡΡΡΡ Π·Π° Π΄ΠΎΠΏΠΎΠΌΠΎΠ³ΠΎΡ ΡΡΠ½Π΅Π»ΡΠ²Π°Π½Π½Ρ Π΅Π»Π΅ΠΊΡΡΠΎΠ½ΡΠ² ΡΠ΅ΡΠ΅Π· ΠΏΠΎΡΠ΅Π½ΡΡΠΉΠ½Ρ Π±Π°Ρ'ΡΡΠΈ, Π²ΡΠ΄ΠΏΠΎΠ²ΡΠ΄Π½Ρ Π΄ΡΠ΅Π»Π΅ΠΊΡΡΠΈΡΠ½ΠΈΠΌ ΠΌΡΡΡΠΊΠ°Ρ
.ΠΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΠ΅ ΠΈΠ½Π΄ΠΈΡ ΠΈΠ½Π΄ΠΈΡ Π² ΠΏΠΎΡΠΈΡΡΠΎΠΌ ΡΡΠ΅ΠΊΠ»Π΅ Ρ ΡΠ°Π·ΠΌΠ΅ΡΠΎΠΌ ΠΏΠΎΡ 7 Π½ΠΌ Π±ΡΠ»ΠΎ ΠΈΠ·ΡΡΠ΅Π½ΠΎ Π²
ΠΈΠ½ΡΠ΅ΡΠ²Π°Π»Π΅ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ 2,3-300 K. ΠΠ±Π½Π°ΡΡΠΆΠ΅Π½ΠΎ, ΡΡΠΎ ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΡΠΉ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π» ΠΏΡΠ΅ΡΠ΅ΡΠΏΠ΅Π²Π°Π΅Ρ ΠΏΠ΅ΡΠ΅Ρ
ΠΎΠ΄ Π²
ΡΠ²Π΅ΡΡ
ΠΏΡΠΎΠ²ΠΎΠ΄ΡΡΠ΅Π΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ TC = 3,9 K. Π Π΅Π·ΠΊΠΈΠΉ Π°ΡΡΠΈΠΌΠ΅ΡΡΠΈΡΠ½ΡΠΉ ΠΏΠΈΠΊ Π½Π° ΠΊΡΠΈΠ²ΠΎΠΉ R(T)
ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½ ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ 6,4 K. ΠΠΏΠ΅ΡΠ²ΡΠ΅ R(T) Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π° Π΄Π»Ρ Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ°Π·Ρ. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ Π² ΠΈΠ½ΡΠ΅ΡΠ²Π°Π»Π΅ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ 15-80 K ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½Π°Ρ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΡ ΠΎΠΏΠΈΡΡΠ²Π°Π΅ΡΡΡ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠΌ ΡΡΠ½Π½Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π½ΠΎΡΠΈΡΠ΅Π»Π΅ΠΉ Π·Π°ΡΡΠ΄Π° Π² ΡΠ°ΠΌΠΊΠ°Ρ
ΠΌΠΎΠ΄Π΅Π»ΠΈ Π¨Π΅Π½Π³Π°. ΠΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΡΠΉ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π» ΠΌΠΎΠΆΠ½ΠΎ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡ ΠΊΠ°ΠΊ ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈ Π½Π΅ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½ΡΠΉ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π», Π² ΠΊΠΎΡΠΎΡΠΎΠΌ ΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΈΠ΅
ΠΎΠ±Π»Π°ΡΡΠΈ Π² ΠΏΠΎΡΠ°Ρ
ΠΊΠΎΠ½ΡΠ°ΠΊΡΠΈΡΡΡΡ ΠΌΠ΅ΠΆΠ΄Ρ ΡΠΎΠ±ΠΎΠΉ ΠΏΠΎΡΡΠ΅Π΄ΡΡΠ²ΠΎΠΌ Π΄ΠΈΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΌΠΎΡΡΠΈΠΊΠΎΠ² ΠΌΠ°ΡΡΠΈΡΡ ΠΈΠ· ΡΡΠ΅ΠΊΠ»Π°. ΠΠ΅ΡΠ΅Π½ΠΎΡ Π·Π°ΡΡΠ΄Π° ΠΌΠ΅ΠΆΠ΄Ρ ΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΎΠ±Π»Π°ΡΡΡΠΌΠΈ ΠΏΡΠΎΠΈΡΡ
ΠΎΠ΄ΠΈΡ ΠΏΠΎΡΡΠ΅Π΄ΡΡΠ²ΠΎΠΌ ΡΡΠ½Π½Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ»Π΅ΠΊΡΡΠΎΠ½ΠΎΠ² ΡΠ΅ΡΠ΅Π· ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΡΠ΅ Π±Π°ΡΡΠ΅ΡΡ, ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠΈΠ΅ Π΄ΠΈΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΠΌ ΠΌΠΎΡΡΠΈΠΊΠ°ΠΌ.Electrical resistance of indium in 7 nm-pore glass has been studied in the temperature 2.3-300 K interval.
It was found that material under study undergoes the transition into the superconducting state at
TC = 3.9 K. A sharp asymmetric R(T) maximum was found at temperature of 6.4 K. The R(T) dependence
has been for the first time analyzed for the normal phase. It was found that the temperature dependence of
the resistance in the temperature 15-80 K interval can be described by tunnelling mechanism of the charge
carriers in the frames of the Shengβs model. Material under study can be considered as electrically inhomogeneous
material in which metallic domains in pores are contacting each other via dielectric bridges of
glass matrix. A charge transfer between the metallic domains can be realized by the electron tunneling
through the potential barriers corresponding to the dielectric bridges
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