Abstract
We have studied the field-induced magnetic structures in , in a wide temperature () and field () range, by single crystal polarized and unpolarized neutron diffraction, with axis. A ferromagneticlike structure with propagation vector is induced, whose local order at low field and low temperature is akin to spin ice. The four Tb ions separate in and chains having different values of the magnetic moments, which is quantitatively explained by taking the crystal field anisotropy into account. Above 2 T and below 2 K, an antiferromagneticlike structure with is induced besides the structure. It shows a reentrant behavior and extends over a finite length scale. It occurs together with a broadening of the nuclear peaks, which suggests a field-induced distortion and magnetostriction effect.
- Received 7 July 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.196402
©2008 American Physical Society