Possibility of an ordered state of spins and holes in single-crystal La2-xSrxCu1-yZnyO4 (x=0.21, y=0 and 0.01) studied by mu SR

Zero-field (ZF) and longitudinal-field (LF) muon spin relaxation (mu SR) me asurements have been carried out in the overdoped single crystals of La2-xS rxCu1-yZnyO4 with x=0.21, y=0 and 0.01. In the case of the Zn-substituted c rystal with x=0.21 and y=0.01 in which the high-T-c superconductivity is al most suppressed, the ZF- and LF-mu SR measurements have revealed the existe nce of a static ordered state of Cu spins at low temperatures below 2 K. No clear coherent precession of the muon spin has been observed down to 20 mK . Slowing down of the Cu-spin fluctuations has also been observed in the no n-Zn-substituted crystal with x=0.21 and y=0 at low temperatures below abou t 0.8 K in ZF, indicating that the observed magnetic anomaly is an intrinsi c property at x=0.21. These mu SR results suggest a strong possibility of t he existence of a spin/charge ordered state at x=0.21 in the overdoped regi on.