A 3D finite elements micromagnetic simulation of a ferromagnetic particle

Different PDEs are derived assuming that local moment rotates as a rigid current loop.PDEs are solved through the FEM by directly applying the weak form.The NIST Standard Problem #3 is solved by calculating full magnetization loops.Different reversal mechanisms are obtained as the particle׳s size increases.

In this work a finite elements method is used to simulate the magnetic behavior of a cubic ferromagnetic particle. The partial differential equations of magnetization are derived assuming that the local moment rotates as a rigid current loop. The three equations for the magnetization and the one for the magnetic scalar potential are solved simultaneously by directly applying the weak form. Using for the cubic particle the same magnetic characteristics as those of NIST Standard Problem #3, full magnetization loops are taken at different particle sizes up to 100 times the exchange length. The results indicate the magnetization reversal mechanisms, such as the coherent rotation, the curling, the formation and propagation of a magnetic wall.