Localization and coercivity of random granular nanomagnets - art. no. 012401

We study the spin configurations of the random granular nanomagnets in the strong to intermediate pinning limit by Monte Carlo simulations. The differ ence in spin configurations at zero and finite field is localized. A deloca lization transition takes place at a critical field. We develop an analytic method to understand the localization pattern of the difference in spin co nfigurations. We also analytically calculate the finite temperature coerciv e field and find good agreement with our Monte Carlo results.