Abstract
The magnetization process of a quasi-one-dimensionaltriangular-lattice antiferromagnet CsNiCl3 has been investigated upto 110 T using a single-turn coil technique. The magnetizationincreases with upturned curvature and reaches a saturation value of2.15μ B/Ni2+ around 73.5 T. From the saturation value andfield, the {g}-value and the intrachain interaction J/kB aredetermined as g=2.15 and J/kB=-13.2 K by assuming that theinterchain interaction is negligible. The magnetization for 1.5 Kobserved in low fields can quantitatively be explained by thespin-wave theory with the 1/S correction at zero temperature. Themagnetization for 5 K in high fields coincides with the result of thequantum Monte Carlo simulation at finite temperature for theHeisenberg antiferromagnetic chain of S=1. This means that the quantumfluctuations in the three-dimensional ordered state dominate themagnetization process in low fields, whereas the characteristics ofthe Heisenberg antiferromagnetic chain do in high fields.
