The Influence of Gaussian Magnetic Pulse on Magnetization Dynamic in Permalloy Thin Films

Abstract

The application of magnetic pulses in the picosecond range has an impact on magnetization reversal rates, which is critical for spintronic device performance. This study investigates the influence of the Gaussian magnetic pulse's width and height on changes in magnetization dynamics in permalloy thin films. To evaluate these magnetization dynamics, micromagnetic simulations based on the Landau-Lifshitz-Gilbert (LLG) equation were employed. The Gaussian pulse width was varied from 200 to 2000 ps, with the corresponding magnetic field magnitudes being 200 mT and 500 mT. The results show that increasing the width and height of the Gaussian magnetic field pulse increases the magnetization reversal rate until it reaches a critical value. For 200 mT of magnetic field induction, the critical pulse width is 1000 ps, while for 500 mT, it is 800 ps. The Gaussian magnetic pulse induction causes reductions and fluctuations of Zeeman energy, exchange energy, and demagnetization energy. These results demonstrate that a large magnetic field at a slight pulse width or a low magnetic field at a broad pulse width can reverse the magnetization of permalloy thin films.