AN O-17 NMR-STUDY OF HG0.5TL0.5BA2(CA1-XSRX)2CU3O8+DELTA

Abstract

We have obtained O-17 nuclear magnetic resonance spectra of magnetically aligned Hg0.5Tl0.5Ba2(Ca1-xSr(x))2Cu3O8+delta at 300 K. The principal components of the electric-field gradient and the Knight-shift tensors are obtained for all oxygen sites in this mercury-based triple Cu-O layered superconductor. The results show that both the EFG and Knight shift tensors of the inner CuO2 plane oxygens are considerably smaller than those of the outer CuO2 plane oxygens, indicating a smaller spin susceptibility and a reduced hole density in the inner CuO2 plane.