Evidence for spin solitons and their dynamics in a spin-Peierls system (DMe-DCNQI)2Li -: art. no. 174413

A spin-Peierls system (DMe-DCNQI)(2)Li has been studied with electron paramagnetic resonance (EPR) under hydrostatic pressure. A definite frequency dependence of the EPR linewidth is observed for the Curie spins that appear below T-SP, demonstrating a clear one-dimensional diffusive character similar to t-(CH)(x). This is strong evidence for Curie spins to arise from spin solitons as domain walls caused by structural defects. The estimated extent of the spin soliton is less than several molecular units. A relation with the antiferromagnetic ordering provoked by impurities as found in CuGeO3 is discussed.