## Abstract

We studied the switching time of a single spin in a field varying linearly in time using a micromagnetics simulation based on the Landau-Lifshitz-Gilbert equation. The applied field larger than the switching field or coercivity is not enough for a spin to switch but some duration of time is also necessary. We found that the value of C _{1} defined by C _{1}= (H - H _{1}) dt was constant when the rate of change in the field was larger than 10× γH _{k} ^{2}, where γ is the gyromagnetic ratio with g value = 2, H is the applied field, H _{1} is a constant, and H _{k} is the anisotropy field of the spin. The integration is taken from the time the spin begins switching to the switching time. The equation is a generalized form of the equation, C _{0} (H - H _{0})τsw, in a constant field H. Here, C _{0} and H _{0} are constants, and τ _{sw} is the switching time. We found that C _{1} in the region dH/dt >10 ×γH _{K} ^{2} and C _{0} in the region H≫H K are the same, but that H _{1} does not coincide with H _{0}. We found that the head field rise time has a very small effect on the switching field and time of recording media.

Original language | English |
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Article number | 123907 |

Journal | Journal of Applied Physics |

Volume | 111 |

Issue number | 12 |

DOIs | |

Publication status | Published - 2012 Jun 15 |

## ASJC Scopus subject areas

- Physics and Astronomy(all)