Predicted properties of Nd1.5Ce0.5Sr2Cu2NbO10 and related high-temperature superconductors

Abstract

The charge-reservoir oxygen model of superconductivity predicts a critical temperature of Tc≈30K for R1.5Ce0.5Sr2Cu2MO10 (R222M−10) (with R=Eu, Sm, and Nd, and M=Ta and Nb), in agreement with the measured values ≈28 K. The model also successfully predicts RBa2Cu2MO8 (R122M−8) to be an insulator. Other predictions for R222M−10 in need of testing are (i) it is a p-type superconductor; (ii) the superconductivity originates primarily in the Sr-O layers, not in the cuprate-planes; (iii) on cuprate-plane Cu sites, of order ∼1% Ni should depress Tc to zero, while about six times as much Zn will be required to destroy superconductivity; (iv) magnetic impurities on Cu sites and Sr sites, but not rare-earth sites, will break Cooper pairs; (v) Pr on Sr sites will suppress Tc; (vi) the failure of Pr1.5Ce0.5Sr2Cu2MO10 to superconduct is due to the antistructure defect (PrSr+3,SrPr+2); (vii) Tc is small because the primary superconducting condensate in the charge-reservoir Sr-O layers is only ≈2 Å from the cuprate-planes; and (viii) the superconductivity should disappear with heavy Ce doping (z→1) in R2−zCezSr2Cu2MO10. The relationships of R222M−10 to R122M−8, RBa2Cu3O7, and R2−zCezCuO4 are discussed.

Source-reported materials — not catalogue approval

Similar papers