Bw. Statt et Lm. Song, SCREENING OF THE MIDDLE CUO2 LAYER IN BI1.6PB0.4SR2CA2CU3O10 DETERMINED FROM CU NMR, Physical review. B, Condensed matter, 48(5), 1993, pp. 3536-3539
Knight-shift measurements of the Cu-63 nuclei in the sandwiching Cu(2)
O2 layers and the middle Cu(1)O2 layer in the three-layer bismuth oxid
e superconductor have been performed. Spin-lattice-relaxation measurem
ents reveal a larger spin-fluctuation enhancement at the Cu(1) sites r
elative to the Cu(2) sites. This and a reduced spin susceptibility in
the Cu(1)O2 layer indicates that the Cu(2)O2 layers screen the charge
transfer from the bismuth bilayer to the Cu(1)O2 layer. Our results sh
ow that the Cu(1)O2 layer has distinctly different physical properties
than the Cu(2)O2 layer.