Magnetoelastic coupling and symmetry breaking in the frustrated antiferromagnet alpha-NaMnO2.
The magnetic and crystal structures of the alpha-NaMnO2 have been determined by high-resolution neutron powder diffraction. The system maps out a frustrated triangular spin lattice with anisotropic interactions that displays two-dimensional spin correlations below 200 K. Magnetic frustration is lifted through magneto-elastic coupling, evidenced by strong anisotropic broadening of the diffraction profiles at high temperature and ultimately by a structural phase transition at 45 K. In this low-temperature regime a three-dimensional antiferromagnetic state is observed with a propagation vector k=(1/2,1/2,0).
Giot
Maud
M
Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, Vassilika Vouton, 71110 Heraklion, Greece.
Chapon
Laurent C
LC
Androulakis
John
J
Green
Mark A
MA
Radaelli
Paolo G
PG
Lappas
Alexandros
A