Structural and Magnetic Properties of the Kagome Antiferromagnet YbBaCo4O7

Journal Article · Sun Jan 01 04:00:00 EST 2006 · J. Solid State Chem.

DOI:https://doi.org/10.1016/j.jssc.2006.01.010· OSTI ID:914000

Huq, A; Mitchell, J; Zheng, H; Chapon, L; Radaelli, P; Knight, K; Stephens, P

The mixed-valent compound YbBaCo{sub 4}O{sub 7} is built up of Kagom{acute e} 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 9x}Ga{sub 12-9x}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{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.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 914000
• Report Number(s): BNL--78568-2007-JA
• Journal Information: J. Solid State Chem., Journal Name: J. Solid State Chem. Journal Issue: 4 Vol. 179; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
DIMENSIONS
MAGNETIC PROPERTIES
MAGNETS
NEUTRONS
NSLS
SYMMETRY
SYNCHROTRONS
X-RAY DIFFRACTION
national synchrotron light source