Spin dynamics in K-doped polyacetylene

Summary form only given. The proton spin-lattice relaxation time (T/sub I/) of a stretched K-doped polyacetylene sample has been measured as a function of the Larmor frequency. The data are in good agreement with the proton relaxation due to a pseudo-1D diffusion of the electron spins. Knowing the density of the states at the Fermi level from TEP and spin susceptibility mesurements, the intrachain spin diffusion rate and the anisotropy are estimated D/sub /// 1.6 x 10/sup 16/ rad s/sup -1/ and D/sub /// / D/spl perp/ /spl sim/ 10/sup 5/. This leads to a microscopic intrachain conductivity, /spl sigma//sub intra/ /spl ap/ 5 x 10/sup 3/ S cm/sup -1/, somewhat higher, but consistent with the macroscopic dc value, /spl sigma//sub /// = 1.1 x 10/sup 3/ S cm/sup -1/. An alternative interpretation of the data in terms of nuclear relaxation mainly due to fixed electronic spins is discussed.