Comment on 'Magnetic Relaxations of Antiferromagnetic Nanoparticles in Magnetic Fields'

摘要

We have carried out in ferritin the Field-Cooling method and data analysisproposed by Mamiya et al. (Phys. Rev. Lett. 88, 67202 (2002) at T = 5 K inorder to check the time magnetic relaxation of these antiferromagneticnanoparticles as a function of the magnetic field. We found that relaxation atT = 5 K in ferritin is faster in the absence of magnetic field, in goodagreement with the zero-field Resonant Spin Quantum Tunneling observedpreviously in ferritin (Phys. Rev. Lett. 79, 1754 (1997).