이우영 A. Samad T.A. Moore J.A.C. Bland B.C. Choi 2024-01-21T14:12:36Z 2024-01-21T14:12:36Z 2022-01-10 2000-03 2469-9950 https://pubs.kist.re.kr/handle/201004/141514 We report the dynamic hysteresis behavior of epitaxial single ferromagnetic NiFe, Co layers, and NiFe/Cu/Co spin-valve structures investigated as a function of field sweep rate (Formula presented) in the range 0.01-270 kOe/sec using the magneto-optic Kerr effect. In situ reflection high-energy electron-diffraction images confirmed that the NiFe, Cu, and Co layers grew epitaxially in the (100) orientation where the fcc NiFe, Co〈110〉 in-plane directions correspond to the Si〈100〉 directions. For (Formula presented) and (Formula presented) single magnetic layer structures, the hysteresis loop area A is found to follow the scaling relation (Formula presented) with (Formula presented) and ∼0.02 at low sweep rates and ∼0.70 and ∼0.30 at high sweep rates, respectively. This result indicates that the NiFe and Co layers in the spin-valve structures can be expected to show distinct scaling behavior at high sweep rate. We found that the “double-switching” behavior which occurs at low sweep rates transforms to “single switching” at ∼154 kOe/sec and ∼192 kOe/sec, respectively, for the single and double spin valves due to the different dynamic response of the NiFe and Co layers. Our results provide direct experimental evidence that the magnetic anisotropy strength affects dynamic hysteresis scaling in ultrathin magnetic films, in contrast with the predictions of current theoretical models. ？ 2000 The American Physical Society. English AMER PHYSICAL SOC Magnetization reversal dynamics in epitaxial spin-valve structures Article 10.1103/PhysRevB.61.6811 1 Physical Review b, v.61, no.10, pp.6811 - 6815 Physical Review b 61 10 6811 6815 N scopus 000085985800053 2-s2.0-0042181870 Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Materials Science Physics Article HYSTERESIS MODEL SYSTEMS FILMS magnetization reversal dynamics epitaxial thin films spin-valve structures