1H nuclear magnetic resonance (NMR) measurements in [YPc2]0, an organic compound formed by radicals stacking along chains, are presented. The temperature dependence of the macroscopic susceptibility, of the NMR shift and of the spin-lattice relaxation rate 1/T1 indicate that the unpaired electron spins are not delocalized but rather form a S=1/2 antiferromagnetic chain. The exchange couplings estimated from those measurements are all in quantitative agreement. The low-energy spin dynamics can be described in terms of diffusive processes and the temperature dependence of the corresponding diffusion constant suggests that a spin-gap around 1 K might be present in this compound.
@article{arxiv.1011.1141,
title = {Low-energy spin dynamics in the [YPc2]0 S=1/2 antiferromagnetic chain},
author = {F. Branzoli and P. Carretta and M. Filibian and S. Klyatskaya and M. Ruben},
journal= {arXiv preprint arXiv:1011.1141},
year = {2015}
}