MAGNETIC-PROPERTIES OF SINGLE-CRYSTALLINE UCU3AL2

UCu3Al2 crystallizes in an ordered variant of the hexagonal CaCu5 stru cture. By neutron powder-diffraction, the U atoms were found to occupy the 1a sites, while the 2c sites are occupied by Cu atoms only and a random occupation of the 3g sites by the remaining Cu and Al is found. The magnetic susceptibility, measured on a single crystal grown by th e Czochralski triarc technique, is found to be maximal within the hexa gonal basal plane with a maximum at about 10 K. For fields applied wit hin the basal plane, the magnetization at 4.2 K exhibits a slight S-sh ape starting slightly below 15 T. No such anomalies are found for fiel ds applied along the c-axis where the magnetic response is found to be much lower. No additional magnetic peaks, which could be related with long-range antiferromagnetic ordering, were detected in the neutron p owder-patterns at low temperatures.