摘要
Exchange bias in NiCo/FeMn bilayers is established by alternating current （magnetic） field cooling, and stripe domains are induced as manifested by the ＂double＂ hysteresis loop. Only one resonance peak occurs at high magnetic fields in the in-plane ferromagnetic resonance spectra. The exchange field measured by both the magnetometry and ferromagnetic resonances is inversely proportional to the ferromagnetic layer thickness tFM. More remarkably, the exchange field determined by the ferromagnetic resonance is smaller than that of the magnetometry measurements. It is suggested to arise from the misalignment of the unidirectional anisotropie directions in neighboring domains.
Exchange bias in NiCo/FeMn bilayers is established by alternating current （magnetic） field cooling, and stripe domains are induced as manifested by the ＂double＂ hysteresis loop. Only one resonance peak occurs at high magnetic fields in the in-plane ferromagnetic resonance spectra. The exchange field measured by both the magnetometry and ferromagnetic resonances is inversely proportional to the ferromagnetic layer thickness tFM. More remarkably, the exchange field determined by the ferromagnetic resonance is smaller than that of the magnetometry measurements. It is suggested to arise from the misalignment of the unidirectional anisotropie directions in neighboring domains.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 50625102 and 50871030, the National Basic Research Program of China under Grant NoS 2009CB929201 and 2006CB921300, and Shanghai Leading Academic Discipline Project under Grant No B113.
