On the Role of Fermi Energy in Determining Properties of Superconductors: a Detailed Comparative Study of Two Elemental Superconductors (Sn and Pb), a Non-cuprate (MgB 2 ) and Three Cuprates (YBCO, Bi-2212 and Tl-2212)

A Detailed Study of the Role of Fermi Energy in Determining Properties of Superconducting NbN

“…As predictions, this process also yields the values of m*, n s , and 0 v via equations derived in [8] and noted in …”

“…Recalled below from [8] are some of the equations that we need for NbN. In these equations 0 W is to be identified with 0 ∆ .…”

“…Based on the data in [17] ther of these equations must be less than 0.5 in order to satisfy the Bogoliubov constraint, and (iii) for any value of 0 0 , T j increases as μ is increased. with the input of a 0 from Table 1 and the atomic masses of the N b and N, as in [8].…”

“…The proposed approach requires, besides the values of T c and ∆ , another property of the SC in order to determine E F . Upon choosing critical current density 0 j of the SC, new equations for both elemental and composite SCs valid at T = 0 were recently presented in [8] for j 0 and the following of their properties: m*, 0 v , and n s , which denote, respectively, the effective mass of superconducting electrons, their critical velocity at which 0 ∆ vanishes, and the density of superconducting electrons. While the results of such a study for Sn, Pb, MgB 2 , YBCO, Bi-2212, and Tl-2212 were also reported in [8],…”

“…In Section 2 are reproduced from [8] those equations that constitute our framework in the OPEM scenario, which may be defined as one in which the T c of an SC can be accounted for by a value of the interaction parameter λ that satisfies the Bogoliubov constraint, i.e., λ < 0.5. Section 3 is devoted to derivation of the new equation for y .…”