High-frequency domain-wall motion and magnetization rotation of patterned permalloy films under external magnetic field excitation

The incorporation of ferromagnetic materials into integrated microwave devices is a promising approach for the development of on-chip high-performance circuit components. Therefore, high-frequency domain-wall motion and magnetization rotation, which yield permeability, are of primary interest. However, so far it has not been attempted to physically separate high-frequency domain-wall motion and magnetization rotation that are under high-frequency magnetic field excitation. Nor have there attempts for the corresponding characterizations. In this work, patterned permalloy films are integrated with on-chip microstrip lines. Domain-wall motion and magnetization rotation are separated through aspect ratio and dimension control. The measured results show that highfrequency-field driven domain-wall motion is fast, different from current driven domain-wall motion. It is also shown that coupling effects are not important when the distance between two adjacent permalloy films is ∼ 1 μm despite their large lateral dimensions. The experimental results agree with simulation results.