Stochastic effect on thermally magnetization reversal in Pico second ordering process

Conference of Theoretical Physics and Nonlinear Phenomena 2014: "From Universe to String's Scale"

Sadnawanto, W.^1 ; Purnama, Budi^1

Physics Department, Post-Graduate Program Sebelas Maret University, Jl. Ir. SUtami 36A Kentingan, Jebres Surakarta

57126, Indonesia^1

关键词: Anisotropy constants;    External fields;    Landau-Lifshitz-Gilbert equations;    Magnetic field direction;    Magnetization reversal dynamics;    Micromagnetic simulations;    Second order process;    Stochastic effects;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/539/1/012024/pdf
DOI  :  10.1088/1742-6596/539/1/012024

来源: IOP

【 摘 要 】

In this study a magnetization reversal dynamics observed in the heat assisted magnetization reversal of CoPtCr perpendicularly magnetized material in the order of a pico second ordering time. Observation of heat assisted magnetization reversal have been using micromagnetic simulation solved by the Landau-Lifshitz-Gilbert equation. The magnetic dot size of the simulation was 50 nm × 50 nm × 20 nm. The perpendicularly anisotropy constant CoPtCr was 2 × 106 erg/cc. Micro-magnetic simulations was carried out systematically by providing pulse-external field with varying pulse duration of 25 ps to 1 ns. The decrease of the minimum field required for reversal observed in this simulation until it reached 90% for 125 ps cooled ordering time. The results also was showed that this sequence simulation running had a zero probability of switching at zero fields. It was indicated that the heat stochastic effect dominated in the mechanism reduced of the field was required for along to the magnetic field direction.