scholarly journals Сверхпроводимость эвтектического сплава Bi-Sn

2021 ◽  
Vol 63 (2) ◽  
pp. 208
Author(s):  
М.В. Лихолетова ◽  
Е.В. Чарная ◽  
Е.В. Шевченко ◽  
Ю.А. Кумзеров
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Magnetic Fields ◽  
Field Dependence ◽  
Proximity Effect ◽  
Coherence Length ◽  
Eutectic Composition ◽  
Positive Curvature ◽  
Two Stage ◽  
Effect Model

We present results of studies of superconductivity in a binary Bi-Sn alloy of the eutectic composition (57 wt.% Bi, 43 wt.% Sn). Temperature and field dependences of the dc magnetization were measured within a temperature range from 1.8 to 20 K in magnetic fields up to 20 kOe using a Quantum Design MPMS3 SQUID magnetometer. A two-stage phase transition with temperatures of the diamagnetism onset of 8.55 and 5.1 K was observed. A phase diagram was constructed. The coherence length for the first stage was estimated. The field dependence of the irreversibility temperature was found. Critical dependencies showed a positive curvature which was treated within the framework of the proximity effect model.

scholarly journals CRYSTAL-FIELD EFFECTS IN THE FIRST-ORDER VALENCE TRANSITION IN YbInCu4 INDUCED BY EXTERNAL MAGNETIC FIELD

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3306-3306 ◽  
Author(s):  
M. DZERO
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Phase Diagram ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Crystal Field ◽  
Valence Transition ◽  
First Order ◽  
Field Effects ◽  
Wide Range

As it was shown earlier [Dzero, Gor'kov and Zvezdin, J. Phys.: Condens. Matt.12, L711 (1000)], the properties of the first-order valence phase transition in YbInCu4 in the wide range of magnetic fields and temperatures are perfectly described in terms of a simple entropy transition for free Yb ions. Within this approach, the crystal field effects have been taken into account and we show that the phase diagram in the B - T plane acquires some anisotropy with respect to the direction of an external magnetic field.

scholarly journals Динамическая восприимчивость нанокомпозита пористое стекло/Ga-In-Sn в области сверхпроводимости

2022 ◽  
Vol 64 (1) ◽  
pp. 40
Author(s):  
О.Д. Шевцова ◽  
М.В. Лихолетова ◽  
Е.В. Чарная ◽  
Е.В. Шевченко ◽  
Ю.А. Кумзеров ◽  
...  
Keyword(s):  
Proximity Effect ◽  
Positive Curvature ◽  
Ac Susceptibility ◽  
Superconducting Phase ◽  
Self Healing ◽  
Activation Barriers ◽  
Nanostructured Alloys ◽  
Effect Model ◽  
Gallium Alloys ◽  
Critical Lines

Interest to studies of gallium alloys increased recently in relation to their prospective applications for self-healing superconducting connections and wires. Special attention is focused on superconductive properties of nanostructured alloys. In the present work we studied the ac susceptibility of a porous glass/Ga-In-Sn nanocomposite within the temperature range from 1.9 to 8 K at bias fields up to 5 T. Two superconducting phase transitions were revealed with temperatures of 5.6 and 3.1 K. Phase diagrams were created. Positive curvature of the parts of critical lines was demonstrated and treated within the framework of a proximity effect model. Vortex activation barriers were found from shifts of the maxima of the imaginary parts of susceptibility with changing the ac frequency. A bend was shown on the field dependence of the activation barriers.

PHASE DIAGRAM FOR ASYMMETRIC PLANAR FERMIONIC SYSTEMS IN THE PRESENCE OF EXTERNAL FIELDS

2012 ◽  
Vol 14 ◽  
pp. 467-474
Author(s):  
RUDNEI O. RAMOS ◽  
PEDRO H. A. MANSO
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Magnetic Fields ◽  
Chemical Potential ◽  
Chiral Symmetry Breaking ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
External Fields ◽  
Asymmetric System ◽  
Fermionic Systems

The phase diagram of planar fermionic systems, with four-fermion interactions, are studied when external magnetic fields in different directions are applied to the system. The application of external fields can lead to an asymmetric system, which with the combined effects due to temperature and chemical potential, can lead to a rich phase diagram with multiple critical points. The phase transition we are primarily interested in studying is that of the metal-insulator type, in which our model is particularly well suitable. The relation between the phase transition with chiral symmetry breaking and the emergence of a gap (or the presence of a nonvanishing chiral vacuum expectation value) in the planar fermionic system, as a function of the different magnetic fields applied, is analyzed in details. The applications of our results in the context of condensed matter and quantum field theory at low dimensions are discussed.

scholarly journals Electric properties of olive oil under pressure

2021 ◽  
Author(s):  
L. T. Pawlicki ◽  
R. M. Siegoczyński ◽  
S. Ptasznik ◽  
K. Marszałek
Keyword(s):  
Molecular Structure ◽  
Phase Transition ◽  
Phase Diagram ◽  
Phase Transitions ◽  
Olive Oil ◽  
Material Parameters ◽  
First Order ◽  
Long Time ◽  
Capacitive Reactance ◽  
First Order Phase

AbstractThe main purpose of the experiment was a thermodynamic research with use of the electric methods chosen. The substance examined was olive oil. The paper presents the resistance, capacitive reactance, relative permittivity and resistivity of olive. Compression was applied with two mean velocities up to 450 MPa. The results were shown as functions of pressure and time and depicted on the impedance phase diagram. The three first order phase transitions have been detected. All the changes in material parameters were observed during phase transitions. The material parameters measured turned out to be the much more sensitive long-time phase transition factors than temperature. The values of material parameters and their dependence on pressure and time were compared with the molecular structure, arrangement of molecules and interactions between them. Knowledge about olive oil parameters change with pressure and its phase transitions is very important for olive oil production and conservation.

scholarly journals Topological nematic phase transition in Kitaev magnets under applied magnetic fields

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Masahiro O. Takahashi ◽  
Masahiko G. Yamada ◽  
Daichi Takikawa ◽  
Takeshi Mizushima ◽  
Satoshi Fujimoto
Keyword(s):  
Phase Transition ◽  
Magnetic Fields ◽  
Nematic Phase

scholarly journals Specific heat of CeRhIn5 in high magnetic fields: Magnetic phase diagram revisited

2021 ◽  
Vol 103 (4) ◽  
Author(s):  
S. Mishra ◽  
A. Demuer ◽  
D. Aoki ◽  
I. Sheikin
Keyword(s):  
Phase Diagram ◽  
Magnetic Fields ◽  
Specific Heat ◽  
Magnetic Phase ◽  
Magnetic Phase Diagram ◽  
High Magnetic Fields

scholarly journals An integrated approach to understanding RF vacuum arcs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Norem ◽  
Z. Insepov ◽  
A. Hassanein
Keyword(s):  
Magnetic Fields ◽  
Failure Analysis ◽  
Field Dependence ◽  
Atom Probe Tomography ◽  
General Model ◽  
Surface Damage ◽  
Integrated Approach ◽  
Atom Probe ◽  
Vacuum Arc ◽  
Stage Model

AbstractAlthough used in the design and costing of large projects such as linear colliders and fusion tokamaks, the theory of vacuum arcs and gradient limits is not well understood. Almost 120 years after the isolation of vacuum arcs, the exact mechanisms of the arcs and the damage they produce are still being debated. We describe our simple and general model of the vacuum arc that can incorporate all active mechanisms and aims to explain all relevant data. Our four stage model, is based on experiments done at 805 MHz with a variety of cavity geometries, magnetic fields, and experimental techniques as well as data from Atom Probe Tomography and failure analysis of microelectronics. The model considers the trigger, plasma formation, plasma evolution and surface damage phases of the RF arc. This paper also examines how known mechanisms can explain the observed sharp field dependence, fast breakdown times and observed surface damage. We update the model and discuss new features while also pointing out where new data would be useful in extending the model to a wider range of frequencies.

ANISOTROPIC VORTEX DYNAMICS AND PHASE DIAGRAM OF YBa2Cu3O7 SINGLE CRYSTALS WITH CANTED COLUMNAR DEFECTS

1996 ◽  
Vol 10 (22) ◽  
pp. 2723-2743 ◽  
Author(s):  
D. S. REED ◽  
N.-C. YEH ◽  
W. JIANG ◽  
U. KRIPLANI ◽  
M. KONCZYKOWSKI ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Magnetic Fields ◽  
Vortex Dynamics ◽  
Flow Model ◽  
Flux Flow ◽  
Thermally Activated ◽  
Liquid Transition ◽  
Columnar Defects ◽  
Thermally Activated Flux Flow ◽  
Activated Flux

The anisotropic vortex dynamics and phase diagram are determined for a YBa 2 Cu 3 O 7 single crystal with columnar defects oriented at ±7.5° relative to the crystalline c-axis. A second-order splayed-glass to vortex-liquid transition is manifested for magnetic fields nearly parallel to the columns via the critical scaling of vortex AC and DC transport properties. In contrast, for magnetic fields aligned close to the ab-plane, an XY-like vortex-glass transition prevails. For magnetic fields at intermediate angles, there is no evidence of any vortex phase transition, and the vortex dynamics is described in terms of the thermally activated flux flow model.

Magnetic phase transition of DyCu2 induced by high magnetic fields

1990 ◽  
Vol 90-91 ◽  
pp. 49-50 ◽  
Author(s):  
Y. Hashimoto ◽  
A. Yamagishi ◽  
T. Takeuchi ◽  
M. Date
Keyword(s):  
Phase Transition ◽  
Magnetic Fields ◽  
Magnetic Phase Transition ◽  
Magnetic Phase ◽  
High Magnetic Fields
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