Field noise in tunneling magnetoresistance sensors with variable sensitivity
Field noise in tunneling magnetoresistance sensors with variable sensitivity
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DOI：
10.1063/1.4907621
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发表时间：
2015-02-02
影响因子：
4
通讯作者：
Wrona, J.
中科院分区：
文献类型：
--
作者：
Wisniowski, P.;Dabek, M.;Wrona, J.
我们展示了CoFeB/MgO/CoFeB传感器的磁场噪声水平低于磁噪声灵敏度缩放限制和1/f噪声拐角频率的显着降低。该传感器显示出超过三个数量级的电压噪声降低和拐角频率从100 kHz下降到1 kHz。我们通过将传感器的场灵敏度从127（V/T）改变为2.7（V/T），通过垂直各向异性诱导的场灵敏度调制来实现这一点。超过比例限制的场噪声的降低呈现了用于特定场灵敏度的传感器。我们的传感器中的场灵敏度调制可实现磁噪声降低，从而改善场噪声（检测率）并将磁1/f角移到较低频率。1/f转角频率的偏移以及磁噪声的降低表明各向异性引起的灵敏度调制在降低CoFeB/MgO/CoFeB传感器中的低频磁化波动方面的重要性。(C)2015 AIP Publishing LLC.
We demonstrate CoFeB/MgO/CoFeB sensors with field noise level below magnetic noise-sensitivity scaling limit and significant reduction of 1/f noise corner frequency. The sensors show more than three orders of magnitude reduction of voltage noise and drop of the corner frequency from 100 kHz to 1 kHz. We achieved this by changing the sensors field sensitivity from 127 (V/T) to 2.7 (V/T) via perpendicular anisotropy-induced field sensitivity modulation. The reduction of the field noise beyond the scaling limit presents sensors for specific field sensitivity. The field sensitivity modulation in our sensors enables magnetic noise reduction that improves field noise (detectivity) and shifts magnetic 1/f corner to lower frequency. The shift of 1/f corner frequency together with the magnetic noise reduction indicates importance of anisotropy-induced sensitivity modulation in reduction of low frequency magnetization fluctuations in CoFeB/MgO/CoFeB sensors. (C) 2015 AIP Publishing LLC.