Evidence of random magnetic anisotropy in ferrihydrite nanoparticles based on analysis of statistical distributions

Abstract

We show that the magnetic anisotropy energy of antiferromagnetic ferrihydrite depends on the square root of the nanoparticles volume, using a method based on the analysis of statistical distributions. The size distribution was obtained by transmission electron microscopy, and the anisotropy energy distributions were obtained from ac magnetic susceptibility and magnetic relaxation. The square root dependence corresponds to random local anisotropy, whose average is given by its variance, and can be understood in terms of the recently proposed single phase homogeneous structure of ferrihydrite.

arXiv comment6 pages, 2 figures

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Cited by in corpus (4)

• Surface anisotropy broadening of the energy barrier distribution in magnetic nanoparticles
• Temperature dependence of antiferromagnetic susceptibility in ferritin
• Shifted loops and coercivity from field imprinted high energy barriers in ferritin and ferrihydrite nanoparticles
• Human brain ferritin studied by muon Spin Rotation: a pilot study