THE CRYSTAL AND MAGNETIC-STRUCTURES OF SR2LAFE3O8

The crystal and magnetic structures of the anion-deficient perovskite Sr2LaFe3O8 (space groupPmma,a = 5.5095(1), b = 11.8845(5), c = 5.6028(1)AÅ) have been refined from X-ray and neutron powder diffraction data collected at room temperature. The crystal structure consists of layers of octahedral (O) and tetrahedral (T) iron-oxygen polyhedra arranged in the stacking sequence ... OOTOOT ... perpendicular to theŷaxis of the unit cell. The magnetic structure is that of a G-type antiferromagnet with ordered magnetic moments of 3.77(5) and 3.15(11) μB at the octahedral and tetrahedral sites, respectively. The low moment at the tetrahedral site is consistent with the observed disorder and magnetic anisotropy. © 1990 Academic Press, Inc.