Static and dynamic magnetic susceptibilities of lightly-doped Bi 2.4Sr 1.6CuO 6+y were studied by a SQUID magnetometer and triple-axis neutron spectrometers. The static magnetic susceptibility showed a difference between field-cooled and zero-field-cooled processes at low temperature, showing a spin-glass-like behavior. The irreversibility temperature was determined to be T sg ̃ 3 K, which is slightly lower than T sg of 5-6 K in the lightly-doped LSCO with similar hole concentration. Furthermore, we have confirmed the existence of low-energy spin fluctuations with the spatially modulated spin correlation along diagonal to Cu-O bond direction in the Bi2201 system for the first time. This observation is consistent with the previously reported result for the spin-glass phase of LSCO. The magnetic intensity χ"(ω) measured at the energy transfer of 1 meV drastically developed below 100 K, while that at 6 meV shows a gradual increase below 200 K with decreasing the temperature. Although the spin fluctuations slow down upon cooling, no well defined static order was detected even at 6 K. Our results suggest that the diagonal incommensurate spin correlation is common in the spin-glass phase of single layer cuprate-oxide. The development of static component, however, is different between the Bi2201 and LSCO systems and would be affected by the interlayer coupling and/or the cation disorder on the A-site.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)