Low-temperature neutron diffraction study of the crystal and magnetic phase transitions in DyCrO4

The crystal and magnetic structures of DyCrO4 were studied using neutron powder diffraction. Complete diffraction data at 3.6, 17, 27, and 40 K show that a crystal structural phase transition from tetragonal I41/amd to orthorhombic Imma symmetry is found to take place between 27 and 40 K. This transition does not involve a significant change in the unit cell volume. Strong ferromagnetic reflections are observed at 3.6 and 17 K, and can be fit well using the magnetic model of space group Im'ma', with the moments of both Dy3+ and Cr5+ ions aligning along the y-axis. Detailed temperature dependent magnetic intensities of 101/011 and 211/121 peaks reveal a Curie temperature of Tc=22.35(15) K.