Abstract
The crystal and magnetic structures of have been studied by x-ray and neutron-diffraction techniques using nearly stoichiometric samples. We find a strong structural anomaly near the antiferromagnetic ordering In addition, the octahedra in exhibit an intrinsic distortion, which implies a splitting of the levels. Our results indicate that should be considered as a Jahn-Teller system where the structural distortion and the resulting level splitting are enhanced by the magnetic ordering.
- Received 4 February 2003
DOI:https://doi.org/10.1103/PhysRevB.68.060401
©2003 American Physical Society