Transport and μSR studies at p∼1/8 in the Bi-2212 and Y-123 phases

The so-called 1/8 effect, namely, the anomalous suppression of superconductivity at the hole concentration per Cu in the CuO2 plane, p, ∼1/8 has been investigated in the partially Zn-substituted Bi-2212 and Y-123 phases by measuring the Hall effect and the muon spin relaxation (μSR). The Hall angle has been found to exhibit large enhancement at p approximately 1/8 in Bi2Sr2Ca1-xYx (Cu1-yZny)2O8δ with y = 0.025. In YBa2Cu3-2yZn2yO7-δ with y = 0.025, anomalous enhancement of the muon spin depolarization has been observed at p approximately 1/8, indicating that the magnetic correlation between Cu spins is enhanced at p approximately 1/8. These results support the stripe model and the proposition that the 1/8 effect is common to all high-Tc cuprates with the CuO2 plane