Structure and magnetism of hydronium jarosite, a model Kagome antiferromagnet.
J CHEM SOC FARADAY T
We have determined the structure of a synthetic sample of the mineral hydronium jarosite by powder neutron diffraction, locating all the hydrogen atoms. Octahedrally coordinated Fe3+ ions are linked through their vertices to produce Kagome layers of moments with a coverage of ca. 95 +/- 4%, depending on the synthesis conditions. Magnetic susceptibility measurements indicate strong coupling of these moments, with a Curie-Weiss constant of -1200 K; but there is no evidence for long-range magnetic order in neutron powder diffraction patterns taken down to 1.5 K. Instead, we observe an anomaly in the magnetic susceptibility at 17.2 K which is a characteristic of spin-glass freezing and similar to experimental work and theory for other Kagome antiferromagnets.
|Title:||Structure and magnetism of hydronium jarosite, a model Kagome antiferromagnet|
|Keywords:||SPIN-GLASSES, LATTICE, PRECIPITATION, FRUSTRATION, ORDER, ION|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry
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