Calculated ferrite nanocrystal relaxation and its magnetic implications

Abstract

Electrostatically driven relaxation and resulting strain-induced magnetic anisotropy may contribute significantly to the magnetic properties of colloidal preparations of ferrite nanocrystals. Preliminary molecular dynamic calculations are described which predict an expansion of a few per cent in a nanocrystal relative to the bulk. A linear extrapolation of strain-induced magnetic anisotropy suggests that such an expansion may give rise to a stress-effective field comparable to the magnetic anomalies observed in these systems.