Intergrain exchange interaction estimation from the remanence magnetization analysis

Analysis of delta m(H) = [M-d(H) - M-r(infinity) + 2M(r)(H)]/M-r(infinity) curves constructed from dc demagnetization and isothermal remanent magnetization (M-d(H) and M-r(H) respectively) is important for characterization of the interactions in ferromagnets. Up to nosy, it has been mainly used for qualitative deductions about them. In this work, the novel functional relation between the maximum of the delta m(H) plot and the microscopic parameters of the weakly coupled Stoner-Wohlfarth ensemble with the isotropic distribution of easy magnetization axes was established using computer modeling. It allows quantitative analysis in the frame of the model to be performed. Finally, a new method of estimating the intergrain exchange interaction constant for nanostructured high anisotropy magnets could be formulated taking into account the results of the modeling. (C) 2014 Elsevier B.V. All rights reserved.