Controllable Domain Walls in Two-Dimensional Ferromagnetic Material Fe3GeTe2 Based on the Spin-Transfer Torque Effect

Recently, two-dimensional magnetic material has attracted attention worldwide due to its potential application in magnetic memory devices. The previous concept of domain walls driven by current pulses is a disordered motion. Further investigation of the mechanism is urgently lacking. Here, Fe3GeTe2, a typical high-Curie temperature (T-C) two-dimensional magnetic material, is chosen to explore the magnetic domain dynamics by in situ Lorentz transmission electron microscopy experiments. It has been found that the stripe domain could be driven, compressed, and expanded by the pulses with a critical current density. Revealed by micromagnetic simulations, all the domain walls cannot move synchronously due to the competition between demagnetization energy and spin-transfer torque effect. In consideration of the reflection of high-frequency pulses, the disordered motion could be well explained together. The multiple stable states of the magnetic structure due to the weak exchange interaction in a two-dimensional magnet provides complex dynamic processes. Based on plenty of experiments, a cluster of domain walls could be more steady and move more synchronously under the drive of pulse current. The complication of domain wall motions presents a challenge in race track memory devices and two-dimensional magnetic material will be a better choice for application research.

Automated summary

The study investigates the behavior of magnetic domains in the high-Curie temperature two-dimensional magnetic material Fe3GeTe2 under the drive of pulses, revealing complex dynamic processes due to multiple stable states of the magnetic structure. Cluster of domain walls are found to be more stable and move more synchronously under pulse current drive, which poses a challenge in race track memory devices and reinforces the potential of two-dimensional magnetic materials in application research.