Magnetic and neutron diffraction studies on potassium uranate KUO3

The magnetic properties of KUO 3 with the cubic perovskite structure have been studied. It shows an antiferromagnetic-type of transition at ca. 17 K in the magnetic susceptibility vs. temperature curve. Magnetic hysteresis is observed at 4.5 K, but not observed at 20 K. Neutron diffraction measurements have been performed on the powdered KUO 3 below and above the transition temperature. The neutron diffraction pattern measured at 10 K shows no appreciable difference from that measured at 50 K. A small ordered magnetic moment of U 5+ ion will make it very difficult to observe magnetic diffractions, even if a magnetic ordering occurs. If the magnetic spin alignment occurs in a small domain, no magnetic diffraction will be found in the neutron experiments. On the other hand, the magnetic phenomena of KUO 3 have been analyzed on the basis of an octahedral crystal field model.