Tcdepression in theYBa2

Transport and NMR studies of the effect of Ni substitution on superconductivity and the normal-state pseudogap inYBa2CuWilliams1, Tallon2, Dupree3 et al. 1996Phys. Rev. B23180View full textAdd to dashboardCite

“…Within the magnetic pair-breaking model discussed above the small decrease in T 1 can be attributed to the indirect Ruderman-Kittel-Kasuya-Yosida mechanism where there is exchange coupling of the local moment to the conduction band electrons and then exchange coupling to the 89 Y nuclear moment. Direct dipolar coupling of a Ni or Zn moment to the 89 Y nuclear moment is unlikely as it should result in a dramatic reduction in T 1 …”

Diffusion in High-Temperature Superconductors

“…Ni atoms, as distinguished from Fe, tend to occupy the planar Cu(2) sites of YBa2Cu307 [49]. The temperature dependence of the nickel diffusion coefficient in YBaCuO ceramics measured in the temperature range 200 to 500 "C by the radio-tracer technique, exhibits a break at about 400 "C [50].…”

63Cu nuclear magnetic resonance study of Pr1.85Ce0.15Cu1 −xNixO4: Ni-induced spin density oscillation and modification of the low energy spin fluctuations

“…For example, Zn initially reduces the superconducting transition temperature, T c , by ∼10 K/% (Zn in the CuO 2 plane) for hole-doped HTSCs near optimal doping [30][31][32][33], while the initial suppression rate is much smaller in the electron-doped HTSCs where it is ∼1 K/% (Zn in the CuO 2 plane) [34]. Ni has the opposite effect on T c , where T c is initially reduced by ∼20 K/% (Ni in the CuO 2 plane) in the electron-doped HTSCs [34][35][36][37] but it is only initially reduced by up to 4 K/% (Ni in the CuO 2 plane) in the hole-doped HTSC, YBa 2 Cu 3 O 7−d [38] and 12 K/% (Ni in the CuO 2 plane) in the hole-doped HTSC, YBa 2 Cu 4 O 8 [30,[39][40][41][42].…”