Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2011-10-31
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
Scientific paper
We present an analytical derivation of the switching field distribution for a single domain particle from the N\'eel-Brown model in the presence of a linearly swept magnetic field and influenced by thermal fluctuations. We show that the switching field distribution corresponds to a probability density function and can be obtained by solving a master equation for the not-switching probability together with the transition rate for the magnetization according to the Arrhenius-N\'eel Law. By calculating the first and second moments of the probability density function we succeed in modeling rate-dependent coercivity and the standard deviation of the coercive field. Complementary to the analytical approach, we also present a Monte Carlo simulation for the switching of a macrospin, which allows us to account for the field dependence of the attempt frequency. The results show excellent agreement with results from a Langevin dynamics simulation and therefore point out the importance to include the relevant dependencies in the attempt frequency. However, we conclude that the N\'eel-Brown model fails to predict switching fields correctly for common field rates and material parameters used in magnetic recording from the loss of normalization of the probability density function. Investigating the transition regime between thermally assisted and dynamic switching will be of future interest regarding the development of new magnetic recording technologies.
Bergmair Bernhard
Breth Leoni
Brueckl Hubert
Fuger Markus
Heer Rudolf
No associations
LandOfFree
Fundamental switching field distribution of a single domain particle derived from the Néel-Brown model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Fundamental switching field distribution of a single domain particle derived from the Néel-Brown model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fundamental switching field distribution of a single domain particle derived from the Néel-Brown model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-148252