17O NMR study of q = 0 spin excitations in a nearly ideal S = 1/2 1D Heisenberg antiferromagnet, Sr2CuO3, up to 800 K

Electron spin excitation upto 800 k Sr2CuO3 were investigated using ¹⁷O nuclear magnetic resonance (NMR). The temperature dependence of the uniform spin susceptibility was measured by NMR Knight shift. Dynamic spin susceptibility was found to increase with increase in temperature. Results suggested that the increase was due to diffusive contributions and estimated a lower bound on the diffusion constant.