Observation of an Antiferromagnetic Phase in the Bi₂Sr₂CuO_6+y System by the μ⁺SR Technique

抄録

We have observed antiferromagnetic ordering in the insulating phase (x≥0.50) of the single-CuO₂-layer (per unit cell) Bi₂(Sr_1−xLa_x)₂CuO_6+y system. The Néel temperature increases from 10 K to 140 K with increasing La concentration. In this respect the system behaves like other high-T_c copper oxide superconductors. In both x=0.55 and x=0.60 specimens, two hyperfine magnetic fields (45 G and 300 G) were observed at different μ⁺ sites in the crystal.