Field-induced magnetoelastic instabilities in antiferromagnetic molecular wheels.
The magnetic torque of the antiferromagnetic molecular wheel CsFe8 was studied down to 50 mK and up to 28 T. Below about 0.5 K phase transitions were observed at the field-induced level crossings (LCs). Intermolecular magnetic interactions are very weak excluding field-induced magnetic ordering. A magnetoelastic coupling was considered. A generic model shows that the wheel structure is unconditionally unstable at the LCs, and the predicted torque curves explain the essential features of the data well.
Waldmann
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Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland.
Dobe
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Ochsenbein
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Güdel
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HU
Sheikin
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