Thermal switching field distribution of a single domain particle for field-dependent attempt frequency

We present an analytical derivation of the switching field distribution (SFD) at finite temperature for a single domain particle from the Neel-Brown model in the presence of a linearly swept magnetic field. By considering the field dependence of the attempt frequency f(0) in the rate equation, we find enhancement of coercivity compared to models using constant f(0). The contribution of thermal fluctuations to the standard deviation of the switching field H-C derived here reaches values of 10% H-C. Considering this contribution, which has been neglected in previous work, is important for the correct interpretation of measurements of switching field distributions. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4737413]