Impurity effect on spin correlations in lightly doped image Original Research Article

A review is given of the impurity effect on the static spin correlations in lightly doped La2-xSrxCuO4La2-xSrxCuO4 studied by the neutron scattering technique. Zn doping reduces the incommensurability just slightly. On the other hand, Ni doping quickly reduces the incommensurability and restores Néel ordering, indicating a strong effect on hole localization. This suggests that Ni is doped as Ni3+Ni3+ or that doped Ni2+Ni2+ and hole form a strongly bound state with the Zhang–Rice character. It was found that this behavior is universal in a wide range of hole concentration in La2-xSrxCuO4La2-xSrxCuO4 (0.01⩽x⩽0.070.01⩽x⩽0.07).