THE STRUCTURAL CONSEQUENCES OF CHARGE DISPROPORTIONATION IN MIXED-VALENCE IRON-OXIDES .2. THE CRYSTAL AND MAGNETIC-STRUCTURES OF BALAFE2O5.91 AT 5K

Journal article

The crystal structure of the low temperature antiferromagnetic phase of the cubic perovskite BaLa Fe2O5.91 has been refined from neutron powder diffraction data collected at 5 K. Space groupPm-3m, a = 3.9268(1)Å.The magnetic structure is consistent with a simple G-type antiferromagnetism but with an unusually low average magnetic moment of 1.87 μB per Fe atom. An interpretation of the structural and magnetic data is proposed in terms of a charge disproportionation and the simultaneous formation of a charge density wave and a spin density wave, but without any structural distortion. The spin system is envisaged as a random arrangement of cations, nominally Fe3+ and Fe5+ in a 3:1 ratio, with antiferromagnetic coupling between pairs of like atoms, and ferromagnetic coupling between unlike atoms. The compound can thus be described as a Mattis spin glass. © 1990 Academic Press, Inc. All rights reserved.

Authors: Battle, P; Gibb, T; Lightfoot, P; Matsuo, M

• Publication status: Published
• Journal: JOURNAL OF SOLID STATE CHEMISTRY
• Volume: 85
• Issue: 1
• Pages: 38-43
• Publication date: 1990-03-01
• DOI: 10.1016/S0022-4596(05)80057-X
• EISSN: 1095-726X
• ISSN: 0022-4596
• Language: English