Many Band Effects in Cuprate Superconductors

1997 ◽  
Vol 11 (13) ◽  
pp. 585-592
Author(s):  
S. P. Kruchinin ◽  
A. M. Yaremko ◽  
E. V. Mozdor
Keyword(s):  
Experimental Data ◽  
Fermi Level ◽  
Temperature Dependence ◽  
Theoretical Approach ◽  
Cuprate Superconductors ◽  
Electron Pair ◽  
Recent Experimental Data ◽  
Natural Manner ◽  
System A ◽  
Interacting Electrons

The new theoretical approach is proposed for study the states responsible for superconductivity of crystals. Within the frameworks of worked out approach it is shown that in electron–phonon system a class of new so-called coupled states arises. Postulated in BCS method electron-pair states k1 + k2 = 0, s + s′ = 0 are in natural manner included in this class. The model numerical calculations have shown that SC gap depends on number of bands crossing the Fermi level on the momenta k1+k2 = K≠ 0 of interacting electrons and that the temperature dependence of SC gap for HTSC is more complicated (in agreement with the recent experimental data) then predicted in BCS approach.

scholarly journals Interplay of Jahn-Teller Ordering and Spin Crossover in Co(II) Compounds

2020 ◽  
Vol 6 (4) ◽  
pp. 62
Author(s):  
Sophia Klokishner ◽  
Serghei M. Ostrovsky
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Theoretical Approach ◽  
Spin Crossover ◽  
Qualitative And Quantitative ◽  
Jahn Teller ◽  
Quantitative Explanation ◽  
Interionic Interactions

The spin crossover phenomena in Co(II) compounds are in the focus of the present paper. A microscopic theoretical approach for the description of spin transitions in mononuclear Co(II) compounds is suggested. Within the framework of this approach there are taken into account two types of interionic interactions that may be operative in the problem such as the electron-deformational interaction and the cooperative Jahn-Teller interaction arising from the coupling of the low-spin state of the Co(II) ion with the tetragonal vibrations of the nearest surrounding. The different role of these interactions in the spin transformation is demonstrated and discussed. On the basis of developed approach a qualitative and quantitative explanation of the experimental data on the temperature dependence of the magnetic susceptibility for the [Co(pyterpy)2](PF6)2, [Co(pyterpy)2](TCNQ)2⋅DMF⋅MeOH and [Co(pyterpy)2](TCNQ)2⋅MeCN⋅MeOH compounds is given.

DIFFUSION OF LIGHT ADATOMS ON SOLID SURFACES

1995 ◽  
Vol 09 (06) ◽  
pp. 307-318
Author(s):  
L. Y. CHEN ◽  
S. C. YING
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Theoretical Approach ◽  
Temperature Regime ◽  
Quantum Tunneling ◽  
Entire Range ◽  
Solid Surfaces ◽  
Recent Experimental Data ◽  
Thermally Activated ◽  
Theoretical Results

We present a brief review of a theoretical approach to the diffusion of light adatoms that covers the entire range from the classical regime of thermally activated hopping to the low temperature regime of quantum tunneling between adjacent sites. We compare our theoretical results with recent experimental data for the system H/Ni(100). We also contrast our results with those obtained from the quantum transition state approach.

Concentration-Dependence of Self-Interstitial and Boron Diffusion in Silicon

2008 ◽  
Vol 1070 ◽  
Author(s):  
Wolfgang Windl
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Ab Initio Calculations ◽  
Fermi Level ◽  
Total Energy ◽  
Ab Initio ◽  
The Self ◽  
Recent Experimental Data ◽  
Boron Diffusion ◽  
Experimental Values

ABSTRACTIn this paper, we discuss the accuracy of ab-initio calculations for self-interstitial and boron dif-fusion in silicon in light of recent experimental data by de Salvador et al. and Bracht et al. Map-ping the experimental data onto the activation energy vs. Fermi level representation commonly used to display ab-initio results, we show that the experimental results are consistent with each other. While the theoretical LDA value for the boron activation energy as a function of the Fermi level agrees well with experiment, we find for the self-interstitial in line with other calculations an underestimation of the experimental values, despite using total-energy corrections.

Fusion and Breakup Reactions of 17S + 208Pb and 15C + 232ThHalo Nuclei Systems

2015 ◽  
Vol 11 (2) ◽  
pp. 2972-2978
Author(s):  
Fouad A. Majeed ◽  
Yousif A. Abdul-Hussien
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Recent Experimental Data ◽  
Barrier Distribution ◽  
Coupled Channel ◽  
Total Fusion ◽  
Full Quantum

In this study the calculations of the total fusion reaction cross section have been performed for fusion reaction systems 17F + 208Pb and 15C + 232Th which involving halo nuclei by using a semiclassical approach.The semiclassical treatment is comprising the WKB approximation to describe the relative motion between target and projectile nuclei, and Continuum Discretized Coupled Channel (CDCC) method to describe the intrinsic motion for both target and projectile nuclei. For the same of comparsion a full quantum mechanical clacualtions have been preforemd using the (CCFULL) code. Our theorticalrestuls are compared with the full quantum mechaincialcalcuations and with the recent experimental data for the total fusion reaction  checking the stability of the distancesThe coupled channel calculations of the total fusion cross section σfus, and the fusion barrier distribution Dfus. The comparsion with experiment proves that the semiclassiacl approach adopted in the present work reproduce the experimental data better that the full quantal mechanical calcautions. 

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.

Isothermal and isobaric vapour-liquid equilibrium data in the tetrachloromethane-sec-butyl alcohol system

1983 ◽  
Vol 48 (9) ◽  
pp. 2446-2453 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Boiling Point ◽  
Butyl Alcohol ◽  
Correlation Equations ◽  
Wilson Equation ◽  
Liquid Equilibrium ◽  
Raoult’S Law ◽  
System A ◽  
Equilibrium Data ◽  
Alcohol System

Isothermal vapour-liquid equilibrium data at 65, 73 and 80 °C and isobaric ones at 101.3 kPa were measured in the tetrachloromethane-sec-butyl alcohol system. A modified circulation still of the Gillespie type was used for the measurements. Under the conditions of measurement, the system exhibits positive deviations from Raoult's law and minimum boiling-point azeotropes. The experimental data were fitted to a number of correlation equations, the most suitable being the Wilson equation.

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.

scholarly journals EFFECTS OF c-AXIS HOPPING IN THE INTERLAYER TUNNELING MODEL OF HIGH-Tc LAYERED CUPRATES

1999 ◽  
Vol 13 (13) ◽  
pp. 1619-1632
Author(s):  
BIPLAB CHATTOPADHYAY ◽  
A. N. DAS
Keyword(s):  
Experimental Data ◽  
Transition Temperature ◽  
Cuprate Superconductors ◽  
Interlayer Coupling ◽  
Superconducting Gap ◽  
Tunneling Model ◽  
High Tc ◽  
Optimal Doping ◽  
Pair Tunneling ◽  
Layered Cuprates

We consider the interlayer pair-tunneling model for layered cuprates, including an effective single particle hopping along the c-axis. A phenomenological suppression of the c-axis hopping matrix element, by the pseudogap in cuprate superconductors, is incorporated. At optimal doping, quantities characteristic to the superconducting state, such as the transition temperature and the superconducting gap are calculated. Results from our calculations are consistent with the experimental observations with the noteworthy point that, the superconducting gap as a function of temperature shows excellent match to the experimental data. Predictions within the model, regarding T c variation with interlayer coupling, are natural outcomes which could be tested further.

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