Perturbed Angular Correlations Studies in the HgBa2CaCu2O6+delta high-T-C Superconductor

Tania Mendonca (1) , J.G. Correia (2) , H. Haas (2) , Philippe Odier (3) , P. B. Tavares (4) , M.R. da Silva (5) , A.M.L. Lopes (5) , Céline Darie (1) , J.P. Araujo (6, 7)

1 NEEL - MRS - Matériaux, Rayonnements, Structure
2 ITN - Inst Tecnol & Nucl
3 NEEL - MagSup - Magnétisme et Supraconductivité
4 Univ Trcisas Os Montes & Alto Douro, Dept Quim, Ctr Quim
5 CFNUL - Centro de Física Nuclear da Universidade de Lisboa
6 IFIMUP - IFIMUP
7 INN - Inst Nanosci & Nanotechnol

The electric field gradients at Hg-199m nuclei have been measured via the perturbed angular correlation (PAC) technique, allowing a full characterization of the Hg neighborhood charge distribution at high oxygen doping on the Hg planes. The PAC technique has been applied to investigate the effect of high oxygen pressure during the measurement. Polycrystalline HgBa2CaCu2O6+delta (Hg-1212) samples have been annealed at 152 bar pressurized oxygen. The influence of oxygen pressure during the experiment was then investigated by measuring the samples at atmospheric pressure and under 152 bar oxygen pressure. The present set of PAC experiments shows that at high oxygen concentrations there is a non-uniform oxygen distribution. Moreover, the Hg environment is not free from oxygen and the results hint to a new type of ordering.

Mots clés: Hg-based superconductors; Oxygen ordering; Local probe techniques

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Tania Mendonca, J.G. Correia, H. Haas, Philippe Odier, P. B. Tavares, et al.. Perturbed Angular Correlations Studies in the HgBa2CaCu2O6+delta high-T-C Superconductor. Journal of Superconductivity and Novel Magnetism, 2011, 24 (3), pp.1153. ⟨10.1007/s10948-010-1099-8⟩. ⟨hal-00978815⟩