Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1486429 | Journal of Non-Crystalline Solids | 2005 | 5 Pages |
Abstract
We report on a dielectric investigation of the glass-like freezing of the orbital reorientation-dynamics, recently found for the crystalline sulfo-spinels FeCr2S4 and FeSc2S4. As the orbital reorientations are coupled to a rearrangement of the surrounding ionic lattice via the Jahn–Teller effect, the freezing of the orbital moments is revealed by a relaxational behavior of the complex dielectric permittivity. Additional conductivity (both dc and ac) and contact contributions showing up in the spectra are taken into account by an equivalent circuit description. The orbital relaxation dynamics continuously slows down over six decades in time, before at the lowest temperatures the glass transition becomes suppressed by quantum tunnelling.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
R. Fichtl, P. Lunkenheimer, J. Hemberger, V. Tsurkan, A. Loidl,