Spin Diffusion in RbMnF3

The spin-diffusion coefficient has been measured in RbMn${\mathrm{F}}_3$ between room temperature ($3.55T_N$) and the critical region ($1.028T_N$). The relationship $D{\left(\kappa a\right)}^{\frac{1}{2}}=22.47\mathrm{}\pm 0.73$ meV ${\mathrm{\AA }}^2$ is well obeyed over this temperature range, and at room temperature the diffusion coefficient has the value 12.86 ± 0.21 meV ${\mathrm{\AA }}^2$. These numerical results are compared with the predictions of dynamic scaling and with theoretical calculations based on the Heisenberg model.