Characterisation of ferromagnetic rings for Zernike phase plates using the Aharonov-Bohm effect
Characterisation of ferromagnetic rings for Zernike phase plates using the Aharonov-Bohm effect
复制标题
DOI：
10.1016/j.ultramic.2012.06.011
复制
发表时间：
2012-09-01
期刊：
影响因子：
2.2
通讯作者：
Barnes, C. H. W.
中科院分区：
文献类型：
--
作者：
Edgcombe, C. J.;Ionescu, A.;Barnes, C. H. W.
对磁化薄膜钴环的全息测量已经证明了磁化的洋葱状态和涡旋状态。对于处于涡旋状态的环，通过环的电子路径与在环外行进的电子路径的相位之间的差异被发现在测量误差内与阿哈罗诺夫-玻姆理论非常吻合。因此，铁磁材料薄膜环中的磁通量可以提供透射电子显微镜中相位板所需的相移。当这种类型的环用作相位板时，散射电子将在与环宽度相似的径向范围内被拦截。厚度为 20nm 的钴环可以从略低于 30nm 的宽度产生 pi/2 的相位差，这表明此类相位板的径向截距范围可以相应较小。 (C) 2012 Elsevier B.V. 保留所有权利。
Holographic measurements on magnetised thin-film cobalt rings have demonstrated both onion and vortex states of magnetisation. For a ring in the vortex state, the difference between phases of electron paths that pass through the ring and those that travel outside it was found to agree very well with Aharonov-Bohm theory within measurement error. Thus the magnetic flux in thin-film rings of ferromagnetic material can provide the phase shift required for phase plates in transmission electron microscopy. When a ring of this type is used as a phase plate, scattered electrons will be intercepted over a radial range similar to the ring width. A cobalt ring of thickness 20nm can produce a phase difference of pi/2 from a width of just under 30nm, suggesting that the range of radial interception for this type of phase plate can be correspondingly small. (C) 2012 Elsevier B.V. All rights reserved.