EFFECT OF SURFACE ANISOTROPY ON THE COERCIVE FIELD OF SMALL MAGNETIC PARTICLES

Monte Carlo calculations were used to study the coercive behavior of s mall spherical ferromagnetic particles as a function of particle size and temperature. The influence of the surface anisotropy on the coerci ve field is discussed. Enhancement of the coercive field compared to i ts bulk value is observed in particles surrounded by a spherical cell with enhanced anisotropy while in the pure ferromagnetic particles an enhanced surface anisotropy with the easy axis normal to the surface d oes not give such enhancement. These results are in agreement with exp erimental findings. (C) 1997 American Institute of Physics.