Abstract
The magnetoelastic excitations of spin frustrated ZnCrO are studied by the magnetic field dependence of the thermal conductivity down to 50 mK. Above the first-order magnetostructural transition at ≈ 12.5 K, spin fluctuations are strongly coupled to acoustic phonons, leading to a glasslike dependence of (), up to . In the symmetry broken phase below , shows a dominant magnetic contribution even at the lowest temperatures probed in this work. Application of a magnetic field above 2.5 T destabilizes the spin-bond structure, leading to a sudden increase and a nonconventional temperature dependence of the thermal conductivity. The possibility of the coexistence of gapped and gapless excitations in this magnetic phase is discussed.
- Received 5 April 2013
DOI:https://doi.org/10.1103/PhysRevB.87.174436
©2013 American Physical Society