Distinguishable effects of oxygen and rhenium in HgBa2CuO4¿d superconductors

L. FABREGA; J. FONTCUBERTA; A. SERQUIS; A. CANEIRO

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2000 vol. 62 p. 4148 - 4153

1098-0121

Muon spin relaxation and magnetization experiments on Hg12xRexBa2CuO41d ceramics with differentoxygen and Re contents allow us to discern the effects of the incorporation of both elements in this superconductor.For all compositions, Tc and s;l22 are strongly dependent on d and display a maximum at optimaldoping. The optimal Tc and s values are nearly independent of x, thus indicating that the Re substitution hasonly second order effects on the basic superconducting properties of this compound, near optimal doping.Samples with Re have higher oxygen contents, due to the high valence of this cation. However, the shift of theTc(d ) and s~d! curves toward higher d values as x increases suggests that the oxygen atoms coordinating theRe cations are less effective to doping than the excess oxygen atoms present in Re-free samples.