Crystal and magnetic structures of the brownmillerite compound Ca{sub 2}Fe{sub 1.039(8)}Mn{sub 0.962(8)}O{sub 5}

Journal Article · Thu Jan 15 00:00:00 EST 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.10.010· OSTI ID:21212171

Ramezanipour, Farshid; Cowie, Bradley; Derakhshan, Shahab ^[1]; Greedan, John E ^[1]; Cranswick, Lachlan M.D. ^[2]

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1. Department of Chemistry, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada)
2. Canadian Neutron Beam Centre, National Research Council, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (Canada)

The crystal and magnetic structures of the brownmillerite material, Ca{sub 2}Fe{sub 1.039(8)}Mn{sub 0.962(8)}O{sub 5} were investigated using powder X-ray and neutron diffraction methods, the latter from 3.8 to 700 K. The compound crystallizes in Pnma space group with unit cell parameters of a=5.3055(5) A, b=15.322(2) A, c=5.4587(6) A at 300 K. The neutron diffraction study revealed the occupancies of Fe{sup 3+} and Mn{sup 3+} ions in both octahedral and tetrahedral sites and showed some intersite mixing and a small, {approx}4%, Fe excess. While bulk magnetization data were inconclusive, variable temperature neutron diffraction measurements showed the magnetic transition temperature to be 407(2) K below which a long range antiferromagnetic ordering of spins occurs with ordering wave vector k=(000). The spins of each ion are coupled antiferromagnetically with the nearest neighbors within the same layer and coupled antiparallel to the closest ions from the neighboring layer. This combination of intra- and inter-layer antiparallel arrangement of spins forms a G-type magnetic structure. The ordered moments on the octahedral and tetrahedral sites at 3.8 K are 3.64(16) and 4.23(16) {mu}{sub B}, respectively. - Grapical Abstract: Temperature dependence of the ordered moments at the Mn-rich (octahedral) and Fe-rich (tetrahedral) sites in Ca{sub 2}FeMnO{sub 5}. The G-type magnetic structure is also shown.

• OSTI ID: 21212171
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 1; Other Information: DOI: 10.1016/j.jssc.2008.10.010; PII: S0022-4596(08)00523-9; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANTIFERROMAGNETISM
CALCIUM COMPOUNDS
CRYSTALS
IRON COMPOUNDS
IRON IONS
LAYERS
MAGNETIZATION
MANGANESE COMPOUNDS
MANGANESE IONS
NEUTRON DIFFRACTION
NEUTRON TEMPERATURE
ORTHORHOMBIC LATTICES
OXIDES
SPACE GROUPS
SPIN
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION