A. Ezzir

TL;DR: In this article, a microscopic model for nanoparticles, composed of a core and a surface shell of constant thickness, is presented, where the magnetic state in the particle is described by the anisotropic classical Dirac-Heisenberg model including exchange and dipolar interactions and bulk and surface anisotropy.

TL;DR: In this article, a microscopic model for nanoparticles, composed of a core and a surface shell of constant thickness, is presented, where the magnetic state in the particle is described by the anisotropic classical Dirac-Heisenberg model including exchange and dipolar interactions and bulk and surface anisotropy.

TL;DR: In this article, the effect of an applied magnetic field on the temperature at the maximum of the zero-field-cooled (ZFC) magnetization, MZFC, is studied using the recently obtained analytic results of Coffey et al. for the prefactor of the Neel relaxation time which allow one to precisely calculate the prefactory in the NEEL-Brown model and thus the blocking temperature as a function of the coefficients of the Taylor series expansion of the magnetocrystalline anisotropy.

TL;DR: In this paper, the synthesis of powders of γ-Fe2O3 nanoparticles with different surface chemical states (hydration, sulphato and phosphato complexes), their characterization and zero-field-cooled magnetisation measurements are reported.