Magnetic phase transitions and structural distortion in Nd2CuO4

Abstract Neutron and X-ray diffraction have been used to study the magnetic and structural properties of single crystal Nd 2 CuO 4 . Long range magnetic order of the Cu moments develops at T N =245 K, with a noncollinear antiferromagnetic arrangement of spins. Additional abrupt transitions are observed at 75 K and 30 K, in which a spin reorientation takes place. Bragg peaks associated with the crystal structure are found at the same positions as the magnetic Bragg peaks, and indicate that a distortion of the basic tetragonal structure has occurred above 300 K.