Structural distortion in the antiferromagnetic phase of frustrated MCr_2O4 spinel
Abstract
Owing to the geometrical frustration and the resultant strong degeneracy of ground state inherent to the spinel structure, Cr^3+ based spinels (MCr_2O_4, M=Zn and Cd) have been discussed to show a spin Jahn-Teller transition, accompanied with simultaneous magnetic ordering and structural phase distortion. To explore the novel spin-lattice coupling, we have examined the detailed structure of single crystals of ZnCr_2O_4, using synchrotron radiation and conventional x-ray sources. In addition to the peak split due to the tetragonal distortion, we found the appearance of superlattice peaks with half-integer indices below the phase transition temperature T_s=12 K. This indicates the lattice distortion is by far more complicated than previously thought. We will discuss a relation between the possible spin structure and lattice distortion.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2003
- Bibcode:
- 2003APS..MARN31010U