Two-dimensional superconductivity in stripe-ordered La1.6-xNd0.4SrxCuO4 single crystals

The dc and ac magnetizations of the stripe-ordered La1.6-xNd0.4SrxCuO4 (x=0.10,0.15,0.18) single crystals have been studied systematically under different magnetic-field orientations. It is found that the dc magnetizations M for all the three different doped samples show two diamagnetic steps for H parallel to c, while there is only one for H parallel to ab. The real part M-' of the ac magnetization is similar to that of the dc one and the imaginary part M-' shows two peaks at the temperatures corresponding to the two steps of M-'. For comparison, the dc magnetization of La1.85Sr0.15CuO4 single crystal without static stripe phase has only one transition for H parallel to c. The results suggest that the anisotropic magnetic properties in La1.6-xNd0.4SrxCuO4 are closely related to the decoupling between the CuO2 planes by the static stripe order which causes a two-dimensional superconducting state in the system.