On the ac magnetic susceptibility of spin-chains: solitons in one-dimensional systems

It is shown that relatively simple phenomenological considerations of the motion of thermally activated solitons (kinks of various types) in the single spin chains can explain and describe qualitatively and quantitatively the temperature and frequency behaviour of magnetic susceptibility in ac magnetic fields. The comparison of experimental data and theoretical results allows estimate the number of solitons and “weak” places in correlation regions of a sample.