Structural and magnetic properties of the quaternary oxides Ba{sub 6}Ln{sub 2}Fe{sub 4}O{sub 15} (Ln=Pr and Nd)

Journal Article · Sun Feb 15 00:00:00 EST 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.10.022· OSTI ID:21212189

Abe, Kyosuke ^[1]; Doi, Yoshihiro ^[1]; Hinatsu, Yukio ^[1]; Ohoyama, Kenji ^[2]

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1. Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan)
2. Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

The crystal structures and magnetic properties of the quaternary lanthanide oxides Ba{sub 6}Ln{sub 2}Fe{sub 4}O{sub 15} (Ln=Pr and Nd) are reported. They crystallize in a hexagonal structure with space group P6{sub 3}mc and have the 'Fe{sub 4}O{sub 15} cluster' consisting of one FeO{sub 6} octahedron and three FeO{sub 4} tetrahedra. Measurements of the magnetic susceptibility, specific heat, and powder neutron diffraction reveal that this cluster behaves as a spin tetramer with a ferrimagnetic ground state of S{sub T}=5 even at room temperature. The cluster moments show a long-range antiferromagnetic ordering at 23.2 K (Ln=Pr) and 17.8 K (Nd), and the magnetic moments of the Ln{sup 3+} ions also order cooperatively. By applying the magnetic field ({approx}2 T), this antiferromagnetic ordering of the clusters changes to a ferromagnetic one. This result indicates that there exists a competition in the magnetic interaction between the clusters. - Graphical abstract: Quaternary oxides Ba{sub 6}Ln{sub 2}Fe{sub 4}O{sub 15} (Ln=Pr and Nd) have the Ba{sub 6}Nd{sub 2}Al{sub 4}O{sub 15}-type structure with space group P6{sub 3}mc. In them, the magnetic moments for the ferrimagnetic Fe{sub 4}O{sub 15} cluster (smaller circles: Fe{sup 3+} ions) and Ln{sup 3+} ions (larger ones) cooperatively show an antiferromagnetic ordering at low temperatures.

• OSTI ID: 21212189
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 2; Other Information: DOI: 10.1016/j.jssc.2008.10.022; PII: S0022-4596(08)00562-8; 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
BARIUM COMPOUNDS
GROUND STATES
HEXAGONAL LATTICES
IRON IONS
IRON OXIDES
MAGNETIC FIELDS
MAGNETIC MOMENTS
MAGNETIC SUSCEPTIBILITY
NEODYMIUM OXIDES
NEUTRON DIFFRACTION
PRASEODYMIUM OXIDES
SPACE GROUPS
SPECIFIC HEAT
TEMPERATURE RANGE 0273-0400 K