Successive Magnetic Phase Transitions in Nd₂CuO₄

Abstract

A neutron scattering study on Nd₂CuO₄, a mother material of the electron-doped superconductor (Nd_1−xCe_x)CuO_4−y, was carried out. Reentrant magnetic phase transitions associated with spin reorientation of antiferromagnetic ordering were observed. La₂NiO₄-type order was stabilized in the range 80 K\lesssimT\lesssim250 K and at T\lesssim40 K. Between 40 K\lesssimT\lesssim80 K, La₂CuO₄-type order was realized. Diffuse scattering due to the two-dimensional spin fluctuation was also observed at around T\simeq250 K.