Glauber Slow Dynamics of the Magnetization in a Molecular Ising Chain

The slow dynamics of the magnetization in the paramagnetic phase,
predicted by Glauber for the 1d Ising model, has been observed with ac
susceptibility and SQUID magnetometry measurements in a molecular chain
comprising alternating Co2+ spins and organic radical spins strongly
antiferromagnetically coupled to give a 1d ferrimagnet. An Arrhenius
behavior with activation energy 152 K has been observed for ten decades of
relaxation time and found to be consistent with the Glauber model. We have
extended this model to take into account the ferrimagnetic nature of the
chain as well as its helicoidal crystal structure.