Structural and magnetic properties of the Kagome antiferromagnet YbBaCo{sub 4}O{sub 7}

Journal Article · Sat Apr 15 00:00:00 EDT 2006 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2006.01.010· OSTI ID:20784966

Huq, A ^[1]; Mitchell, J F ^[2]; Zheng, H ^[2]; Chapon, L C ^[3]; Radaelli, P G ^[3]; Knight, K S ^[3]; Stephens, P W ^[4]

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1. Intense Pulsed Neutron Source, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States)
2. Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States)
3. ISIS Facility, Rutherford Appleton Laboratory-CCLRC, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)
4. Department of Physics and Astronomy, SUNY Stonybrook, NY 11794 (United States)

The mixed-valent compound YbBaCo{sub 4}O{sub 7} is built up of Kagome sheets of CoO{sub 4} tetrahedra, linked in the third dimension by a triangular layer of CoO{sub 4} tetrahedra in an analogous fashion to that found in the known geometrically frustrated magnets such as pyrochlores and SrCr{sub 9} {sub x} Ga{sub 12-9} {sub x} O{sub 19} (SCGO). We have undertaken a study of the structural and magnetic properties of this compound using combined high-resolution powder neutron and synchrotron X-ray diffraction. YbBaCo{sub 4}O{sub 7} undergoes a first-order trigonal{sup {yields}}orthorhombic phase transition at 175 K. We show that this transition occurs as a response to a markedly underbonded Ba{sup 2+} site in the high-temperature phase and does not appear to involve charge ordering of Co{sup 2+}/Co{sup 3+} ions in the tetrahedra. The symmetry lowering relieves the geometric frustration of the structure, and a long-range-ordered 3-D antiferromagnetic state develops below 80 K.

• OSTI ID: 20784966
• Journal Information: Journal of Solid State Chemistry, Vol. 179, Issue 4; Other Information: DOI: 10.1016/j.jssc.2006.01.010; PII: S0022-4596(06)00008-9; Copyright (c) 2006 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
BARIUM IONS
COBALT COMPOUNDS
COBALT IONS
CRYSTAL STRUCTURE
LAYERS
MAGNETIC PROPERTIES
NEUTRON DIFFRACTION
OXIDES
PHASE TRANSFORMATIONS
PYROCHLORE
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION
YTTERBIUM COMPOUNDS