Magnetic excitations in triangular lattice NaCrO2 Original Research Article

We report the first inelastic neutron scattering measurements on the rhombohedrally stacked triangular antiferromagnet NaCrO2 which has recently been shown via μμSR and NMR measurements to exhibit an unusually broad fluctuating cross-over regime extending far below the onset of spin freezing at TcTc. Our results show that strong spin fluctuations persist far below TcTc and that dispersive spin wave excitations only appear near the cross-over temperature 0.75Tc0.75Tc.