Superconducting State Parameters of Nb _x Ta _y Mo _z Superconductors

Abstract

We present screening dependence theoretical investigations of the superconducting state parameters, i.e. electronphonon coupling strength 𝜆, Coulomb pseudopotential 𝜇 * , transition temperature 𝑇𝐶 , isotope effect exponent 𝛼, and effective interaction strength 𝑁0𝑉 , of some BMG superconductors, namely Nb0.45Ta0.45Mo0.10, Nb0.30Ta0.40Mo0.30, Nb0.40Ta0.30Mo0.30, Nb0.30Ta0.30Mo0.40 and Nb0.15Ta0.15Mo0.70 by employing the well-known empty core model potential of Ashcroft for the first time. Five local field correction functions proposed by Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. are used in the present investigation to study the screening influence on the aforesaid superconducting properties.The transition temperature 𝑇𝐶 obtained from the 𝐻-local field correction function is found to be in an excellent agreement with the available theoretical data. Also, the present results are found to be in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in the superconductors.

Superconducting state parameters of ternary amorphous superconductors

“…The Ashcroft's empty core (EMC) model potential is a simple one-parameter model potential [15], which has been successfully found for various metallic complexes with various form of the screening functions [3][4][5][6][7][8][9][10][11][12]. Therefore, in the present work we use Ashcroft's empty core (EMC) model potential with more advanced Ichimaru-Utsumi (IU) [ [20] local field correction functions for the first time in the present case.…”

“…In the present work, r C is fitted with experimental T C of the ternary amorphous alloys for most of the local field correction functions. In the present investigation for (Ni 33 Zr 67 ) 1 − x M x (x = 0, 0.05, 0.1, and 0.15, M = Cu) ternary amorphous superconductors, the electronphonon coupling strength λ is computed using the relation [3][4][5][6][7][8][9][10][11][12] …”

“…Influence of the third element on the electronic and electron transport properties of binary metallic glasses has been studied extensively [1][2][3][4] but its effect on superconducting properties has been given lesser attention. Only few researchers studied the superconducting properties of ternary amorphous superconductors using model potential formalism [4][5][6][7][8][9][10][11][12].…”

“…The electron-pseudoion is accounted by the pseudopotential and the electron-electron interaction is involved through a dielectric screening function. For successful prediction of the superconducting properties of the alloying systems, the proper selection of the pseudopotential and screening function is very essential [6][7][8][9][10][11].…”

“…In the present work, the pseudo-alloy-atom (PAA) model was used to explain electron-ion interaction for alloying systems [6][7][8][9][10]. It is well known that the pseudo-alloy-atom (PAA) model is a more meaningful approach to explain such kind of interactions in alloying systems.…”