Abstract
From inelastic neutron scattering the strongly anisotropic spin-wave dispersion curves of a single crystalline sample have been measured at 1.3 K for the main symmetry directions , , and over the entire first Brillouin zone. Least-squares fits to the Holstein-Primakoff spin-wave theory yield the isotropic exchange energy constants, , up to fifth nearest neighbors () as follows: K, K, K, K, K which correspond to a paramagnetic Curie temperature of K. The results confirm previous assumptions that the range of the is essentially limited to next nearest neighbors, and thus agree fairly well with most of the previous experimental results on and . The temperature dependence of the disagrees with the predictions of the spin-wave renormalization theory.
- Received 27 June 1980
DOI:https://doi.org/10.1103/PhysRevB.22.5447
©1980 American Physical Society