We report high resolution neutron scattering measurements on the rhombohedrally stacked triangular antiferromagnet NaCrO2 which has recently been shown to exhibit an unusually broad fluctuating cross-over regime extending far below the onset of spin freezing at Tc. Our results show that at Tc purely two-dimensional quasi-static spin correlations of the 120° type exist. Below some cross-over temperature (T ∼ 0.75 Tc) a small incommensuration develops which helps resolve the inter-layer spin frustration and drives short-range three-dimensional magnetic order. This incommensuration assisted dimensional cross-over suggests that inter-layer frustration is responsible for stabilizing the rare 2D correlated phase above 0.75 Tc.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Low dimensional magnetism
- Neutron scattering
- Triangular lattice