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Field-induced magnetoelastic instabilities in antiferromagnetic molecular wheels

O. Waldmann·C. Dobe·S. T. Ochsenbein·H. U. Güdel·I. Sheikin
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Abstract

The magnetic torque of the antiferromagnetic molecular wheel CsFe8 was studied down to 50 mK and in fields up to 28 T. Below ca. 0.5 K phase transitions were observed at the field-induced level-crossings (LCs). Intermolecular magnetic interactions are very weak excluding an explanation in terms of field-induced magnetic ordering. A magneto-elastic 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.

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O. Waldmann, C. Dobe, S. T. Ochsenbein, H. U. Güdel, I. Sheikin. 2005-11-30. Field-induced magnetoelastic instabilities in antiferromagnetic molecular wheels. https://doi.org/10.1103/physrevlett.96.027206

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