High-gradient nanomagnets on cantilevers for sensitive detection of nuclear magnetic resonance.
High-gradient nanomagnets on cantilevers for sensitive detection of nuclear magnetic resonance.
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DOI：
10.1021/nn3030628
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发表时间：
2012-11-27
期刊：
影响因子：
17.1
通讯作者：
Marohn, John A.
中科院分区：
文献类型：
--
作者：
Longenecker, Jonilyn G.;Mamin, H. J.;Senko, Alexander W.;Chen, Lei;Rettner, Charles T.;Rugar, Daniel;Marohn, John A.
关键词：
磁尖和核自旋之间的力的磁共振检测先前已被证明可以实现低于10纳米分辨率的1H成像。在这种磁共振力显微镜（MRFM）实验中，最大化自旋力需要高场梯度。为了研究大范围的样品，同样需要在力传感器上定位磁尖。在这里，我们报告了具有高梯度钴纳米磁头的attnewton -sensitivity悬臂梁的发展。利用x射线光电子能谱和超导量子干涉仪对磁性材料的损伤层厚度和饱和磁化强度进行了表征。利用移频悬臂式磁强计对单个磁头的矫顽力场和饱和磁化强度进行了原位量化。测量了悬臂梁对磁场的耗散和尖端样品的分离。研究了聚苯乙烯薄膜中质子的MRFM信号与射频辐射频率和尖端-样品分离的关系，并根据这些数据评估了尖端场和尖端场梯度。通过数值模拟磁共振信号的频率依赖性来评估磁尖的性能。我们观察到的尖端场梯度估计在4.4到5.4 MT m - 1之间，这与最近在4 nm分辨率的1H成像实验中使用的梯度相当，并且比之前在磁悬臂上的MRFM实验中获得的梯度大了近一个数量级。
Detection of magnetic resonance as a force between a magnetic tip and nuclear spins has previously been shown to enable sub-10 nm resolution 1H imaging. Maximizing the spin force in such a magnetic resonance force microscopy (MRFM) experiment demands a high field gradient. In order to study a wide range of samples, it is equally desirable to locate the magnetic tip on the force sensor. Here we report the development of attonewton-sensitivity cantilevers with high gradient cobalt nanomagnet tips. The damage layer thickness and saturation magnetization of the magnetic material were characterized by X-ray photoelectron spectroscopy and superconducting quantum interference device magnetometry. The coercive field and saturation magnetization of an individual tip were quantified in situ using frequency-shift cantilever magnetometry. Measurements of cantilever dissipation versus magnetic field and tip-sample separation were conducted. MRFM signals from protons in a polystyrene film were studied versus rf irradiation frequency and tip-sample separation, and from this data the tip field and tip-field gradient were evaluated. Magnetic tip performance was assessed by numerically modeling the frequency dependence of the magnetic resonance signal. We observed a tip-field gradient estimated to be between 4.4 and 5.4 MT m−1, which is comparable to the gradient used in recent 4 nm resolution 1H imaging experiments and larger by nearly an order of magnitude than the gradient achieved in prior magnet-on-cantilever MRFM experiments.
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影响因子：
3.2
作者：
ALBRECHT, TR;GRUTTER, P;RUGAR, D
通讯作者：
RUGAR, D
影响因子：
1.6
作者：
HUTTER, JL;BECHHOEFER, J
通讯作者：
BECHHOEFER, J
影响因子：
4.4
作者：
DIXON, RW;BLOEMBERGEN, N
通讯作者：
BLOEMBERGEN, N
DOI：
10.1073/pnas.1003040107
发表时间：
2010-07-27
影响因子：
11.1
作者：
Felts, Richard L.;Narayan, Kedar;Subramaniam, Sriram
通讯作者：
Subramaniam, Sriram
影响因子：
3.5
作者：
Giorgio, M;Meier, B;Meyer, E
通讯作者：
Meyer, E