Structure and magnetism in Pr3ReO7 and Nd3ReO7—materials with an ordered, defect fluorite structure

Nd3ReO7 and Pr3ReO7 were prepared by solid-state reaction involving Ln2O3, ReO3 and ReO2 in sealed quartz tubes and a carefully controlled thermal sequence. Attempts to prepare the corresponding compound with Ln=La was unsuccessful with the same procedure. The crystal structures were refined from powder neutron diffraction data in space group Cmcm. The unit cell constants (Å) are a=10.941(1), b=7.4565(8) and c=7.5993(9) for Ln=Pr and …