Superconducting State Parameters of Al-Li Binary Alloys (original) (raw)
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Superconducting State Parameters of IN(1-x)-Tl(x) Binary Alloys
Journal for Foundations and Applications of Physics, 2021
A universal model potential of Fiohais et al. with five local field correction functions due to Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used for the first time to study the superconducting state parameters viz. electron-phonon coupling strength , Coulomb pseudopotential * , transition temperature C T , isotope effect exponent and effective interaction strength V N O of binary alloys. Very strong effect of the various local field correction functions is established from the present study. The comparison with other such theoretical values is promising, which confirms the applicability of model potential in clarifying the superconducting natures of binary mixture.
Study of Superconducting State Parameters of Alloy Superconductors
2009
The theoretical study of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ * , transition temperature T C , isotope effect exponent α and effective interaction strength N O V of Pb-Tl-Bi alloys viz. Tl 0.90 Bi 0.10 , Pb 0.40 Tl 0.60 , Pb 0.60 Tl 0.40 , Pb 0.80 Tl 0.20 , Pb 0.60 Tl 0.20 Bi 0.20 , Pb 0.90 Bi 0.10 , Pb 0.80 Bi 0.20 , Pb 0.70 Bi 0.30 , Pb 0.65 Bi 0.35 and Pb 0.45 Bi 0.55 have been made extensively in the present work using a model potential formalism for the first time. A considerable influence of various exchange and correlation functions on λ and μ * is found from the present study. The present results of the SSP are found in qualitative agreement with the available experimental data wherever exist.
Acta Physica Polonica A, 2018
Screening dependence study of the superconductivity in 4d-and 5d-transition metals based binary alloys was performed using the model pseudopotential approach, which was found quite successful in explaining superconductivity in metals, alloys, and metallic glasses. In the present work the superconducting state parameters viz. electron-phonon coupling strength λ, the Coulomb pseudopotential µ * , transition temperature TC , isotope effect exponent α and effective interaction strength N0V of some transition metals based binary alloys of 4d-and 5dtransition metals groups were determined in the BCS-Eliashberg-McMillan framework. A considerable influence of various exchange and correlation functions on λ and µ * is found from the present study. The present results of the superconducting state parameters are found in qualitative agreement with the available experimental figures wherever exist.
Superconducting State Parameters of Binary Superconductors
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A well known pseudopotential is used to investigate the superconducting state parameters viz. electron-phonon coupling strength , Coulomb pseudopotential *, transition temperature ТС, isotope effect exponent and effective interaction strength N0V for the AgxZn1 – x and AgxAl1 – x binary superconductors theoretically for the first time. We have incorporated here five different types of the local field correction functions to show the effect of exchange and correlation on the aforesaid properties. Very strong influence of the various exchange and correlation functions is concluded from the present study. The comparison with other such experimental values is encouraging, which confirms the applicability of the model potential in explaining the superconducting state parameters of binary mixture. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2777
A pseudo-potential approach to superconducting state parameters of certain metals
Czechoslovak Journal of Physics, 1984
Superconducting state parameters, i.e. electron-phonon coupling stregth 2, Coulomb pseudopotential #*, transition temperature T~, isotope effect exponent 0~ and effective interaction strength NoV have been evaluated by employing a linear form of the electron-ion pseudopotential, recently proposed by Sharma and Kachhawa. It is observed that the presently computed values show an overall good agreement with the experimental data and also with the other results available in the literature.
On the calculation of Tc's of superconducting binary alloys based on two-phonon exchange mechanism
Physica B: Condensed Matter, 2004
By making use of the available experimental heat capacity data and a recently proposed equation based on the multiple phonon-exchange mechanism, we present here the results of ab-initio calculation of T c 's of some of the binary superconducting alloys in the following scenarios: (a) the alloy is characterized by a single Debye temperature and (b) the alloy is characterized by two Debye temperatures. The latter scenario follows from the suggestion that phonons corresponding to the two sub-lattices in the alloy simulate, in a first approximation, the modes of vibration of two weakly coupled harmonic oscillators.
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Physical Review B, 2006
We calculated the superconductivity properties of alkali metals under high pressure using the results of band theory and the rigid-muffin-tin theory of Gaspari and Gyorffy. Our results suggest that at high pressures Lithium, Potassium, Rubidium and Cesium would be superconductors with transition temperatures approaching 5 − 20K. Our calculations also suggest that Sodium would not be a superconductor under high pressure even if compressed to less than half of its equilibrium volume. We found that the compression of the lattice strengthens the electron-phonon coupling through a delicately balanced increase of both the electronic and phononic components of this coupling. This increase of the electron-phonon coupling in Li is due to an enhancement of the s-p channel of the interaction, while in the heavier elements the p-d channel is the dominant component.
First-principles studies on the superconductivity of aluminene
Applied Surface Science, 2018
Group III mono-elemental two-dimensional (2D) materials have been an active area of research since the experimental demonstration of monolayer boron. Using first-principles calculations, we predict a new type of buckled monolayer aluminum (aluminene) which exhibits metallic characteristics. From the phonon dispersion and cohesive energy calculations, the free-standing aluminene is structurally stable. The stability of the aluminene is maintained under tensile 2 strain up to 7%. In contrast, the stability of the structure is not preserved in the presence of compressive strain. We also carried out a systematic analysis on the electron-phonon coupling in the aluminene structure and found that aluminene in its pristine form can superconduct with superconductivity critical temperature, of 6.5 K. The is further enhanced to 11.9 K with the presence of 7% bi-axial tensile strain. Our calculations show that the higher Tc is because of stronger electron-phonon coupling resulted from the increase of density of states at Fermi level with tensile strain.
The theory of strong coupling superconductivity in disordered transition metal alloys
Journal of Low Temperature Physics, 1983
The equations of strong coupling superconductivity in disordered transition metal alloys have been derived by means of "'irreducible" Green's functions and on the basis of the alloy version of the Bari~id-Labbd-Friedel model for electron-ion interaction. The configurational averaging has been performed by means of the coherent potential approximation. Making some approximations, we have obtained the formulas for the transition temperature Tc and the electron-phonon coupling constant A. These depend on the alloy component and total densities of states, the phonon Green's function, and the parameters of the model