Abstract
The way geometric frustration in the pyrochlore antiferromagnet HgCr 2O4 is relieved by an applied magnetic field is studied by synchrotron X-ray diffraction. The material shows a structural change, from cubic to orthorhombic, at the magnetic transition temperature, TN ≃ 6 K, to relieve the geometrical frustration. Below TN, successive magnetic phase transitions occur in an applied field, from the antiferromagnetic to the half-magnetization plateau phase followed by a transition with a kink in the magnetization. We find that the lattice constant shows discontinuous expansions that coincide with magnetization changes, indicating progressive relief of geometric frustration. We calculate the lattice deformation invoking a magneto-elastic coupling and obtain good agreement between the calculation and our observation.
Original language | English |
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Article number | 043708 |
Journal | journal of the physical society of japan |
Volume | 76 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2007 Apr |
Keywords
- Geometric frustration
- HgCr O
- High magnetic field
- X-ray diffraction
ASJC Scopus subject areas
- Physics and Astronomy(all)