Atomic ordering of the fluorine dopant in theHgBa2CuO4+δhigh-Tc

Perturbed Angular Correlations Studies in the HgBa2CaCu2O6+δ high-TC Superconductor

“…However, one would expect that the measurement under 152 bar oxygen would lead to strong changes in the fractions of probes interacting with the different EFGs, due to the continuous doping. The slight increase of the fraction of probes interacting with EFG a for the measurement under 152 bar pressurized oxygen together with the fact that Hg-1212 as opposed to Hg-1201 can trap more oxygen, suggests a different ordering than the one reported [15,16].…”

“…EFG b affects 17(4)% of the 199m Hg probe atoms. At a first glance, the non-axially symmetric EFG a could be assigned to 199m Hg nuclei placed in lattice sites with symmetry lower than tetragonal due to the location of oxygen in the Hg mesh, as obtained in Hg-1201 [15,16]. However, one would expect that the measurement under 152 bar oxygen would lead to strong changes in the fractions of probes interacting with the different EFGs, due to the continuous doping.…”

“…EFG b cannot be assigned to any of the configurations reported in refs. [15,16], since those EFG parameters have not been experimentally observed. Furthermore, such high local oxygen concentrations have not been calculated and thus the present experimental results require new simulations.…”

“…Similarly to refs. [15,16], Hg-1212 samples were implanted with 199m Hg (T 1/2 = 42 min) at the ISOLDE/CERN facility [17]. After implantation, the effect of high oxygen pressure during the measurement was investigated.…”

Oxygen ordering in the high-Tcsuperconductor HgBa2CaCu2OMendonça1, Correia2, Haas3 et al. 2011Phys. Rev. BSelf Cite

“…Previous atomic scale studies of oxygen and fluorine dopants have been performed mainly in the 1 st member of this series of compounds (Hg-1201) 14,20,21 . To achieve higher O δ concentrations, we have chosen the 2 nd member of this series, Hg-1212.…”