Several of the magnetically ordered phases of dysprosium aluminum garnet have been studied using neutron-diffraction techniques. At temperatures below the Néel point, the intensities of the magnetic reflections in zero magnetic field exhibit unexpected hysteresis. The intensities obtained after cooling in zero field are significantly different from those obtained after quenching the field to zero at a constant temperature. This behavior is shown to be consistent with a model based on extinction effects which are dependent upon the size of the magnetic domains. The behavior with a magnetic field applied parallel to the [001] and [110] directions has also been studied. For fields along [001] we find at low temperatures a transition to a state in which the spins perpendicular to the field are aligned with a different arrangement than that found in zero field. With the field along [110] we find a low-temperature transition to a state in which the transverse spins appear to be ferromagnetically aligned. These results for the low-temperature—high-field ordered states are in good agreement with the predictions of previous workers.

• Received 9 December 1981

DOI:https://doi.org/10.1103/PhysRevB.25.6886