Successive Magnetic Phase Transitions in Nd₂CuO₄

A neutron scattering study on Nd ₂ CuO ₄ , a mother material of the electron-doped superconductor (Nd _{1- x} Ce _x )CuO _{4- y} , was carried out. Reentrant magnetic phase transitions associated with spin reorientation of antiferromagnetic ordering were observed. La ₂ NiO ₄ -type order was stabilized in the range 80 K\({\lesssim}T{\lesssim}\)250 K and at \(T{\lesssim}40\) K. Between 40 K\({\lesssim}T{\lesssim}\)80 K, La ₂ CuO ₄ -type order was realized. Diffuse scattering due to the two-dimensional spin fluctuation was also observed at around T ≃250 K.