Effect of angle dependent attempt frequency on Arrhenius-Neel thermal decay in thin film media

The angle dependence of the attempt frequency f(o) has been determined by assuming isotropic thermal excitation in the anisotropic free energy around the easy axis of a singe-domain particle, The relationship between the logarithmic time and the time-dependent remanence coercivity N-cr was estimated. The acquired equation agrees well with the numerical calculation of the Langevin equation. The conventional formula do not give the correct relationship between H-cr and K-beta (= Kv/kT) because the exponent of K-beta depends on K-beta. The estimated K-beta from Sharrock's formula is 15% larger at K-beta of 100 and 5% smaller at K-beta of 50, Bertram's formula is effective at Ka of 100 but brings 7% smaller estimation at K-beta of 50.