MAGNETIC-PROPERTIES OF ORDERED PEROVSKITES BA2MUO6 (M=SC, Y, GD, YB, MN)

Uranium complex oxides with the ordered perovskite structure Ba2MUO6 (M = Sc, Y, Gd, Yb, Mn) were prepared, and their magnetic susceptibilities and electron paramagnetic resonance (EPR) spectra were measured. The lattice parameter of the compounds varied linearly with the ionic radius of M3+. The effective magnetic moments of U5+ in Ba2YUO6 and Ba2ScUO6 were very small. The moments of Ba2GdUO6 and Ba2YbUO6 were 7.74 and 4.69 μB, respectively, close to the theoretical values for Gd3+ and Yb3+. The electron paramagnetic resonance spectrum was observed for Ba2GdUO6, its g-value was 1.92. In Ba2MnUO6, ferrimagnetic behavior was found below ca. 55 K. The effective magnetic moment was 5.52 μB and the g -value of EPR was 2.00. These results show that the manganese ion is divalent at a high spin state and that the uranium ion is in the hexavalent state. © 1993 Academic Press. All rights reserved.