標題: | Magnetoimpedance behavior and its equivalent circuit analysis of Co/Cu/Co/Py pseudo-spin-valve with a nano-oxide layer |
作者: | Chien, Wei-Chih Yao, Yeong-Der Wu, Jiann-Kuo Lo, Chi-Kuen Hung, Ruei-Feng Lan, M. D. Lin, Pang 材料科學與工程學系 Department of Materials Science and Engineering |
關鍵字: | annealing;cobalt;copper;equivalent circuits;giant magnetoresistance;inductance;Permalloy;spin valves |
公開日期: | 1-二月-2009 |
摘要: | Magnetoimpedance behaviors and thermal effects of a Co/Cu/Co/Py pseudo-spin-valve (PSV) with a nano-oxide layer (NOL) were studied. The PSV can be regarded as a combination of resistances, inductances, and capacitances. In addition, equivalent circuit theory can be used to analyze the ac behavior of this system. The imaginary part of the magnetoimpedance (magnetoreactance) ratio is more than 1700% at the resonance frequency (f(r))=476 kHz at room temperature (R(T)). The dc magnetoresistance (MR) ratio decreases as the annealing temperature increases because the NOL is formed at the interface between the spacer and the magnetic layer. The NOL deteriorates the differential spin scattering and reduces the dc MR ratio. Impedance spectroscopy was utilized to analyze the capacitance effect from NOL after annealing. The effective capacitance of the PSV was 21.8 nF at R(T) and changed to 11.8 nF after annealing at 200 degrees C. The useful equivalent capacitor circuit not only is a nondestructive measurement technology but can also explain the experimental results and prove the formation of the NOL. |
URI: | http://dx.doi.org/10.1063/1.3075841 http://hdl.handle.net/11536/7706 |
ISSN: | 0021-8979 |
DOI: | 10.1063/1.3075841 |
期刊: | JOURNAL OF APPLIED PHYSICS |
Volume: | 105 |
Issue: | 3 |
結束頁: | |
顯示於類別: | 期刊論文 |