Average energy barriers in disordered interacting magnetic nanoparticles

The saddle points in disordered two-dimensional dipole-coupled systems of magnetic nanoparticles are determined. For this purpose an iterative method is applied which employs the eigenvalues and -vectors of the Hessian matrix. By determining the adjacent minima the average barrier heights and the average distances between saddles and minima are calculated as functions of the positional disorder and the size dispersion of the particle assembly.