Distribution of magnetic anisotropy in nanograins

Universal distribution of magnetic anisotropy of impurities in ordered and disordered nanograins
A. Szilva, P. Balla, O. Eriksson, G. Zaránd, and L. Szunyogh
Phys. Rev. B 91, 134421 (2015)

Radial distribution of the magnetic anisotropy parameters (dots) in the E plane in the case of NS=50 samples with N=225+25 atoms. The continuous line presents the predictions of the Gaussian orthogonal ensemble. Inset: Distribution of (K1,K2) in the E plane for these 50 nanograins. At this level of disorder the triangular structure is almost entirely lost.