Quaternary uranium copper oxides: the structure and properties of UBa2CuO6

Abstract
Investigation of several UVI–CuII oxide fields has shown the existence of only one quaternary oxide, UBa2CuO6. This adopts a cation-ordered perovskite structure with a= 5.78473(8)Å and c= 8.8424(2)Å in tetragonal space group I4/mmm. Magnetic susceptibility measurements show a Curie–Weiss behaviour, characteristic of localised copper(II) spins at high temperatures (50–300 K), with antiferromagnetic ordering below 10 K.