Location of the oxygen dopant in the high temperature superconductor HgBa2CuO4+δ from 199Hg NMR

In the high temperature cuprate superconductor, HgBa2CuO4+delta, it has been determined that the dopant oxygen, O-delta, resides in the Hg-plane. Here we present a systematic investigation of the Hg-199 NMR spectrum as a function of dopant oxygen concentration, delta. At high doping levels we observe four distinct Hg-199 resonance peaks which follow a binomial distribution in S corresponding to zero, one, two, and three nearest neighbor O-delta atoms. Additionally, we have measured a linear dependence of the peak frequencies on doping and suggest that these measurements might be theoretically amenable.