Enhancement of the magnetic anisotropy barrier in critical long range spin systems
Abstract
Magnetic materials are usually characterized by anisotropy energy barriers which dictate the timescale of the magnetization decay and consequently the magnetic stability of the sample. Here we consider magnetization decay for spin systems in a d = 3 cubic lattice with an isotropic Heisenberg interaction decaying as a power law with a critical exponent α = d and onsite anisotropy. We show that the anisotropy energy barrier can be determined from the ergodicity breaking energy of the corresponding isolated system and that, unlike in the case of nearest neighbour interaction, the anisotropy energy barrier grows as the particle volume, V, and not as the crosssectional area.
 Publication:

Journal of Physics Condensed Matter
 Pub Date:
 March 2013
 DOI:
 10.1088/09538984/25/10/106006
 arXiv:
 arXiv:1106.0148
 Bibcode:
 2013JPCM...25j6006B
 Keywords:

 Condensed Matter  Statistical Mechanics;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 7 pages, 6 figures. Theory of Magnetic decay in nanosystem. Non equilibrium statistical mechanics of many body systems