scholarly journals Analytical solutions of the microscopic two-band theory for the temperature dependence of the upper critical fields of pure MgB2compared with experimental data

2011 ◽  
Vol 37 (6) ◽  
pp. 451-458 ◽  
Author(s):  
M. Palistrant ◽  
A. Surdu ◽  
V. Ursu ◽  
P. Petrenko ◽  
A. Sidorenko
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Analytical Solutions ◽  
Critical Fields ◽  
Band Theory ◽  
Upper Critical Fields

scholarly journals Inhomogeneity and irreversibility field of superconducting Nb-Ti tapes

2018 ◽  
Vol 185 ◽  
pp. 08004 ◽  
Author(s):  
Valentin Guryev ◽  
Sergey Shavkin ◽  
Vitaly Kruglov
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Upper Critical Field ◽  
Vortex Matter ◽  
Irreversibility Field ◽  
Superconducting Tapes ◽  
Critical Fields ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Upper Critical Fields

Magnetizations and current-voltage characteristics of superconducting tapes from Nb-50% wt.Ti alloy are studied. In the region of external magnetic fields close to the upper critical field, there is a so called irreversibility field, which is often associated with the phase transition of vortex matter. However, in this study it is shown that the whole volume of experimental data can be described if we abandon the hypothesis of a phase transition and go over to the hypothesis of macroscopic inhomogeneity. This hypothesis implies the existence of two superconducting components with different upper critical fields, which naturally arise as a result of the production process.

Characterization of Inhomogeneities in Amorphous Superconductors

1985 ◽  
Vol 58 ◽  
Author(s):  
Esen E. Alp ◽  
S.K. Malik ◽  
Y. Lepetre ◽  
P.A. Montano ◽  
G.K. Shenoy
Keyword(s):  
Electrical Resistivity ◽  
Electron Diffraction ◽  
Temperature Dependence ◽  
Flux Pinning ◽  
Ac Susceptibility ◽  
Exafs Spectroscopy ◽  
Superconducting Properties ◽  
Critical Fields ◽  
Upper Critical Fields

ABSTRACTThe structure and superconducting properties of rapidly quenched Zr—Ni and Zr—V alloys have been studied by XRD,EXAFS spectroscopy,TEM,electron diffraction,ED, electrical resistivity and ac susceptibility measurements. Amorphous Zr66Ni34 ribbons quenched with different cooling rates were also examined by flux pinning measurements. Characteristic differences are observed in the flux pinning mechanisms of microcrystalline and amorphous samples. The temperature dependence of upper critical fields have been measured down to 0.4 K and the results are analyzed in terms of WHH theory.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

scholarly journals Experimental signatures of nodeless multiband superconductivity in a $$\hbox {2H-Pd}_{0.08} \hbox {TaSe}_2$$ single crystal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chanhee Kim ◽  
Dilip Bhoi ◽  
Yeahan Sur ◽  
Byung-Gu Jeon ◽  
Dirk Wulferding ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Zero Magnetic Field ◽  
Anisotropy Ratio ◽  
Strong Temperature Dependence ◽  
Critical Fields ◽  
Band Theory ◽  
Plane Field ◽  
Low Field ◽  
Out Of Plane

AbstractIn order to understand the superconducting gap nature of a $$\hbox {2H-Pd}_{0.08} \hbox {TaSe}_2$$ 2H-Pd 0.08 TaSe 2 single crystal with $$T_{c} = 3.13 \text { K}$$ T c = 3.13 K , in-plane thermal conductivity $$\kappa $$ κ , in-plane London penetration depth $$\lambda _{\text {L}}$$ λ L , and the upper critical fields $$H_{c2}$$ H c 2 have been investigated. At zero magnetic field, it is found that no residual linear term $$\kappa _{0}/T$$ κ 0 / T exists and $$\lambda _{\text {L}}$$ λ L follows a power-law $$T^n$$ T n (T: temperature) with n = 2.66 at $$T \le \frac{1}{3}T_c$$ T ≤ 1 3 T c , supporting nodeless superconductivity. Moreover, the magnetic-field dependence of $$\kappa _{0}$$ κ 0 /T clearly shows a shoulder-like feature at a low field region. The temperature dependent $$H_{c2}$$ H c 2 curves for both in-plane and out-of-plane field directions exhibit clear upward curvatures near $$T_c$$ T c , consistent with the shape predicted by the two-band theory and the anisotropy ratio between the $$H_{c2}$$ H c 2 (T) curves exhibits strong temperature-dependence. All these results coherently suggest that $$\hbox {2H-Pd}_{0.08} \hbox {TaSe}_2$$ 2H-Pd 0.08 TaSe 2 is a nodeless, multiband superconductor.

scholarly journals Ability of Constitutive Models to Characterize the Temperature Dependence of Rubber Hyperelasticity and to Predict the Stress-Strain Behavior of Filled Rubber under Different Defor Mation States

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 369
Author(s):  
Xintao Fu ◽  
Zepeng Wang ◽  
Lianxiang Ma
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Mechanical Response ◽  
Constitutive Models ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Chain Model ◽  
Stress Strain ◽  
Filled Rubber ◽  
Yeoh Model

In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress–strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress–strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress–strain characteristics of filled rubber.

A novel technique for synthesizing MgB2thin films with high upper critical fields

2008 ◽  
Vol 21 (8) ◽  
pp. 085009 ◽  
Author(s):  
Y Shen ◽  
R Gandikota ◽  
R K Singh ◽  
F L Hunte ◽  
J Jaroszynski ◽  
...  
Keyword(s):  
Critical Fields ◽  
Novel Technique ◽  
Upper Critical Fields
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