SELF-TEST OF SPIN FLUCTUATION PAIRING

The critical self-test of the spin fluctuation pairing model of high-t emperature superconductivity, associated with the relative suppression of T-c by Ni and Zn impurities on Cu sites, has not been satisfied fo r any material for which the test has been performed, including YBa2Cu 3O7. In all high-temperature superconductors that have been measured, except BCS-like Nd2-zCezCuO4, Ni and Zn suppress T-c virtually the sam e, which is inconsistent with cuprate plane superconductivity that res ults from either i) BCS-like (phonon-like) polarization pairing or ii) spin fluctuation pairing. The observed T-c-suppression in all such su perconductors, including Nd2-zCezCuO4, is consistent with BCS-like cha rge-reservoir superconductivity.