Neutron-scattering study of spin correlations in image Original Research Article

We performed a neutron-scattering experiment to investigate the effect of distortion of CuO2CuO2 planes on the low-energy spin correlation of La1.94-xSrxCe0.06CuO4La1.94-xSrxCe0.06CuO4 (LSCCO). Due to the carrier-compensation effect by co-doping of Sr and Ce, LSCCO has a smaller orthorhombic lattice distortion compared to La2-xSrxCuO4La2-xSrxCuO4 (LSCO) with comparable hole concentration p . A clear gap with the edge-energy of 6–7 meV was observed in the energy spectrum of local dynamical susceptibility χ″(ω)χ″(ω) for both x=0.18x=0.18 (p∼0.14p∼0.14) and x=0.24x=0.24 (p∼0.20p∼0.20) samples as observed for optimally doped LSCO (x=0.15–0.18)(x=0.15–0.18). For the x=0.14x=0.14 (p∼0.10p∼0.10) sample, in addition to the gap-like structure in χ″(ω)χ″(ω) we observed a low-energy component within the gap which develops below View the MathML source2–3meV with decreasing the energy. The low-energy component possibly coincides with the static magnetic correlation observed in this sample. These results are discussed from a view point of relationship between the stability of low-energy spin fluctuations and the distortion of CuO2CuO2 planes.