Comment on Magnetic Relaxations of Antiferromagnetic Nanopar(3)

We have carried out in ferritin the Field-Cooling method and data analysis proposed by Mamiya et al. (Phys. Rev. Lett. 88, 67202 (2002) at T = 5 K in order to check the time magnetic relaxation of these antiferromagnetic nanoparticles as a function of the

FIGURECAPTIONS

Figure1:Ratiobetweennon-zero- eldandzero- eldviscositiesasafunctionofthemagnetic eld,H0,recordedatT=5Kinferritin.