The title compounds are the family of the AMO2-type (R3m) crystal which has a pronounced layer structure and are promising candidates for the two-dimensional Heisenberg triangular lattice antiferromagnet (2DH TAL-AF). The interesting observation is that a singular point of the EPR signal is located around TKM=0.66JS2 for the critical temperature of phase transition associated with the pairing-dissociation of the Z2 vortices, suggesting the present system behaves as 2DH TAL-AF down to very close to TKM. The EPR linewidth exhibits Z2 vortex-induced broadening above the critical temperature which is inversely proportional to the thermally excited vortex density, nv∝exp (–Ev/kBT) with the activation energy Ev≅4kBTKM.
All Science Journal Classification (ASJC) codes
- 物理與天文學 (全部)