Micromagnetic modeling of magnetostrictive materials under intrinsic stress

We have developed a framework based on micromagnetics to explore the effect of stress on the magnetostrictive behavior in ferromagnetics. Our approach is different from the conventional one which simply replaces the total strain by magnetostrain. Question arises for such an approach because of the loss of strain compatibility. Here, we have included the kinematic constraints in our micromagnetic model and developed a modified boundary integral formalism to calculate the intrinsic stress induced by incompatible magnetostrain. We have shown that for small magnetostriction of the order of 10(-5), the results predicted by the present approach are slightly different from those predicted by the conventional method. But we have found that for large magnetostriction around 10(-3) order of magnitude, the conventional approach is insufficient to predict magnetic domain patterns and hysteresis precisely, and the effective magnetic field induced by intrinsic stress cannot be neglected. (C) 2003 Elsevier Ltd. All rights reserved.