EXPERIMENTAL PROOF OF 2D SPIN DIFFUSION BY FREQUENCY-DEPENDENCE OF ESR LINEWIDTH

ESR linewidth measurements have been performed on the quasi-two-dimensional Heisenberg magnet (C2H5NH3)2MnCl4 at room temperature in the X-, K-, Q- and V-band. As expected from theory a logarithmic frequency dependence of the magic angle linewidth has been determined, which represents a characteristic feature of spin diffusion in a two-dimensional lattice. The spin diffusion constant is evaluated to be D/a2 = (1700±250) rad GHz. © 1979.