Publication Date:
2014-11-28
Description:
Centimetre-sized single crystals of high-quality CaBaCo2Fe2O7were synthesized by the optical floating zone technique. The metal-to-metal stoichiometry and oxygen content were confirmed by spectroscopy and thermal reduction experiments. The hexagonal symmetryP63mc(No. 186) well describes the powder X-ray and neutron diffraction as well as single-crystal neutron diffraction at all measured temperatures. This symmetry is also consistent with optical second harmonic generation data obtained between 10 and 295 K. However, a satisfactory structure description from single-crystal neutron diffraction data needs an oxygen split position. Specific heat, magnetic susceptibility and powder neutron diffraction data indicate a magnetic phase transition atTN= 159 K to an antiferromagnetic ground state, but with a persisting hexagonal symmetry and intrinsic geometric frustration.
Print ISSN:
0021-8898
Electronic ISSN:
1600-5767
Topics:
Geosciences
,
Physics
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