查看“︁扫描透射电子显微镜”︁的源代码

{{Otheruses|subject=电子显微镜|other=其他條目說明|STEM}}
{{noteTA
|G1=物理學
|T=zh-hans:扫描透射电子显微镜; zh-hant:掃描穿透式電子顯微鏡;
|1=zh-hans:透射电子显微镜; zh-hant:穿透式電子顯微鏡;
|2=zh-hans:检测器; zh-hant:偵測器;
|3=zh-cn:分辨率; zh-tw:解析度
|4=zh-hans:纳米; zh-hant:納米; zh-tw:奈米
}}

[[File:STEM fig.png|thumb|STEM成像示意图。<small>从上至下：电子枪、聚光镜系统、聚光光阑、偏转扫描线圈、上物镜极靴、样品、下物镜极靴、STEM检测器（位于物镜后焦面）</small>]]'''扫描透射电子显微镜'''（{{lang-en|Scanning transmission electron microscope}}；縮寫為'''STEM'''）是利用电磁透镜把电子束会聚成非常小的束斑在薄样品上进行逐点扫描，并利用探测器收集透过样品的-{zh-hans:散射电子; zh-hant:散射電子}-进行成像的一种显微镜技术。其为[[透射电子显微镜]]（TEM）的一种，与传统TEM的区别在于STEM的电子束被汇聚得非常细（束斑大小一般为0.05-0.2 nm）<ref>{{Cite book|title=Practical Materials Characterization|last=Jian Guo Wen|publisher=Springer|year=2014|isbn=978-1-4614-9280-1|location=纽约|pages=189-229|chapter=Transmission Electron Microscopy|doi=10.1007/978-1-4614-9281-8_5|language=en}}</ref>，然后该光斑在光栅照明系统下扫描样品，使得样品在每个点都被平行于光轴的光束照亮。因此可与[[环形暗场成像]]（ADF）、[[能量色散X射线光谱]]（EDX）或[[电子能量损失谱]]（EELS）等分析技术进行联用<ref name=":1" /><ref name=":42" />。

一个典型的STEM是在传统TEM基础上配备了额外的扫描线圈、检测器以及相关电路系统，使得其可在STEM与TEM两种模式间进行切换。当然也有一些专用于STEM的电子显微镜<ref>{{Cite journal |author=E. M. James，N. D. Browning， A. W. Nicholls，et al |title=Demonstration of atomic resolution Z-contrast imaging by a JEOL JEM-2010F scanning transmission electron microscope |journal=Microscopy |year=1998 |volume=47 |issue=6 |page=561-574 |doi=10.1093/oxfordjournals.jmicro.a023629}}</ref>。

STEM可获高分辨率的图像，但这需要稳定的外部环境。外部振动、温度波动、声波以及电磁波都会干扰高分辨率图像的获得<ref>{{cite journal |author1=Muller, D.A. |author2=Grazul, J. |title=Optimizing the environment for sub-0.2 nm scanning transmission electron microscopy |journal=Journal of Electron Microscopy |year=2001 |volume=50 |issue=3 |pages=219–226 |doi=10.1093/jmicro/50.3.219 |pmid=11469410 |doi-access=free}}</ref>。[[File:Stem1.JPG|thumb|配有3级球差矫正器的超高真空STEM设备|202x202px]]
[[File:Abbcorr1.JPG|thumb|磁六极-磁六极型像差校正器内部结构|154x154px]]

==历史==
{{See also|电子衍射|透射电子显微镜#历史|label 1=电子衍射|label 2=透射电子显微镜历史}}

世界首台STEM由德国[[西门子]]的曼弗雷德·冯·阿登纳（Manfred von Ardenne）于1938年发明<ref>{{cite journal |last=von Ardenne |first=M |title=Das Elektronen-Rastermikroskop. Theoretische Grundlagen |journal=Z. Phys. |year=1938 |volume=109 |issue=9–10 |pages=553–572 |bibcode=1938ZPhy..109..553V |doi=10.1007/BF01341584 |s2cid=117900835}}</ref><ref>{{cite journal |last=von Ardenne |first=M |title=Das Elektronen-Rastermikroskop. Praktische Ausführung |journal=Z. Tech. Phys. |year=1938 |volume=19 |pages=407–416}}</ref> ，但这台STEM的成像效果不及当时的[[透射电子显微镜|透射电子显微镜 (TEM)]]，而且阿登纳仅用了两年来处理这个问题，之后不了了之。这台STEM于1944年二战期间被空袭炸毁，然而二战结束后阿登纳再也没有回到西门子继续工作<ref>{{Cite web |url=http://www-g.eng.cam.ac.uk/125/achievements/mcmullan/mcm.htm |title=D. McMullan, SEM 1928 – 1965 |access-date=2024-08-14 |archive-date=2018-10-04 |archive-url=https://web.archive.org/web/20181004024632/http://www-g.eng.cam.ac.uk/125/achievements/mcmullan/mcm.htm |dead-url=no }}</ref>。STEM的发展陷入停滞。

这种停滞直到20世纪70年代[[芝加哥大学]]的阿尔伯特·克鲁（Albert Crewe）发明了[[场致发射|场发射]][[电子枪]]<ref>{{cite journal |last=Crewe |first=Albert V |author2=Isaacson, M. |author3=Johnson, D. |title=A Simple Scanning Electron Microscope |url=https://digital.library.unt.edu/ark:/67531/metadc1061663/ |journal=Rev. Sci. Instrum. |type=Submitted manuscript |year=1969 |volume=40 |issue=2 |pages=241–246 |bibcode=1969RScI...40..241C |doi=10.1063/1.1683910 |access-date=2024-08-14 |archive-date=2024-05-10 |archive-url=https://web.archive.org/web/20240510052330/https://digital.library.unt.edu/ark:/67531/metadc1061663/ |dead-url=no }}</ref>才得以结束。克鲁并在初代STEM的基础上额外添加一个高质量物镜，奠定了现代STEM。克鲁在此基础上使用一个[[环形暗场成像|环形暗场探测器]]实现了对原子的成像。克鲁和其同事随后又开发了[[冷發射|冷场发射]]电子源，实现了利用STEM在碳基底上对单个重原子的成像观测<ref>{{cite journal |last=Crewe |first=Albert V |author2=Wall, J. |author3=Langmore, J. |title=Visibility of a single atom |journal=Science |year=1970 |volume=168 |issue=3937 |pages=1338–1340 |bibcode=1970Sci...168.1338C |doi=10.1126/science.168.3937.1338 |pmid=17731040 |s2cid=31952480}}</ref>。

随后到了80年代末90年代初，STEM的像分辨率达到了2 [[埃米|Å]]（埃米）以下，意味着其可以对某些材料中的原子结构进行成像<ref>{{cite journal |author1=Shin, D.H. |author2=Kirkland, E.J. |author3=Silcox, J. |title=Annular dark field electron microscope images with better than 2 Å resolution at 100 kV |journal=Appl. Phys. Lett. |year=1989 |volume=55 |issue=23 |pages=2456 |bibcode=1989ApPhL..55.2456S |citeseerx=10.1.1.466.7672 |doi=10.1063/1.102297}}</ref>。

===像差校正===
在STEM中添加一个[[像差]]校正器（主要是校正[[球差]]）后电子束斑进一步汇聚减少到亚埃米级，使得成像分辨率步入亚埃米级，这样一来人们能够以前所未有的清晰度观测单个原子柱（atomic column）。1997年像差校正STEM的分辨率达到了1.9 Å<ref>{{cite journal |author1=Batson, P.E. |author2=Domenincucci, A.G. |author3=Lemoine, E. |title=Atomic resolution electronic structure in device development |journal=Microsc. Microanal. |year=1997 |volume=3 |issue=S2 |pages=645 |bibcode=1997MiMic...3S.645B |doi=10.1017/S1431927600026064 |s2cid=250948492}}</ref>，并于2000年提升至约1.36 Å<ref>{{cite journal |last1=Dellby |first1=N. |last2=Krivanek |first2=O. L. |author2-link= |last3=Nellist |first3=P. D. |author3-link= |last4=Batson |first4=P. E. |last5=Lupini |first5=A. R. |title=Progress in aberration-corrected scanning transmission electron microscopy |journal=Microscopy |year=2001 |volume=50 |issue=3 |pages=177–185 |doi=10.1093/jmicro/50.3.177 |pmid=11469406 |doi-access=free}}</ref>。目前更先进的像差校正STEM分辨率可达50 [[皮米|pm]]（0.5 Å）以下<ref>{{cite journal |last1=Kisielowski |first1=C. |last2=Freitag |first2=B. |last3=Bischoff |first3=M. |last4=et al |first4= |last5= |first5= |last6= |first6= |last7= |first7= |last8= |first8= |last9= |first9= |last10= |first10= |last11= |first11= |display-authors= |title=Detection of Single Atoms and Buried Defects in Three Dimensions by Aberration-Corrected Electron Microscope with 0.5-Å Information Limit |journal=Microscopy and Microanalysis |year=2008 |volume=14 |issue=5 |pages=469–477 |bibcode=2008MiMic..14..469K |doi=10.1017/S1431927608080902 |pmid=18793491 |s2cid=12689183 |last12=Uhlemann |first12=S. |last13=Müller |first13=H. |last14=Hartel |first14=P. |last15=Kabius |first15=B. |last16=Miller |first16=D. |last17=Petrov |first17=I. |last18=Olson |first18=E.A. |last19=Donchev |first19=T. |last20=Kenik |first20=E.A. |last21=Lupini |first21=A.R. |last22=Bentley |first22=J. |last23=Pennycook |first23=S.J. |last24=Anderson |first24=I.M. |last25=Minor |first25=A.M. |last26=Schmid |first26=A.K. |last27=Duden |first27=T. |last28=Radmilovic |first28=V. |last29=Ramasse |first29=Q.M. |last30=Watanabe |first30=M.}}</ref>。这种成像能力提升对于实现原子分辨率化学和元素光谱分析至关重要。[[File:Stemschema1.JPG|thumb|像差校正器剖面结构示意图|198x198px]]

==STEM的成像模式==

=== 环形暗场成像（ADF） ===
{{Main|环形暗场成像}}
STEM的'''环形暗场成像'''模式是指利用一个环形检测器收集偏离主透射束方向上的前-{zh-hans:散射电子; zh-hant:散射電子}-进行成像。特别是利用一个高角度环形暗场检测器进行成像时，可以得到原子级分辨率[[原子序数衬度像技术|Z衬度像]]，意味着图像衬度能直接反应对应原子柱的[[原子序数]]相对大小<ref>{{cite journal |author1=Pennycook, S.J. |author2=Jesson, D.E. |title=High-resolution Z-contrast imaging of crystals |url=https://zenodo.org/record/1258469 |journal=Ultramicroscopy |type=Submitted manuscript |year=1991 |volume=37 |issue=1–4 |pages=14–38 |doi=10.1016/0304-3991(91)90004-P |access-date=2024-08-14 |archive-date=2022-12-18 |archive-url=https://web.archive.org/web/20221218190706/https://zenodo.org/record/1258469 |dead-url=no }}</ref>。其与传统的{{le|高分辨电子显微镜|high-resolution electron microscopy}}（HRTEM）像相比，像衬度更容易解释<ref name=":42">{{Cite journal |author=贾志宏，丁立鹏，陈厚文 |title=高分辨扫描透射电子显微镜原理及其应用 |journal=物理 |language=zh-cn |year=2015 |volume=7 |page=446-452 |doi=10.7693/wl20150704}}</ref><ref name=":1">{{Cite journal |author=李超，杨光 |title=扫描透射电子显微镜及电子能量损失谱的原理及应用 |journal=物理 |language=zh-cn |year=2014 |volume=9 |page=597-605 |doi=10.7693/wl20140904}}</ref>。

=== 明场成像（BF） ===
在STEM中，'''明场成像'''模式是采用一个轴向明场检测器置于透射束光锥中心位置，形成一个与环形暗场像衬度相反的明场像<ref>{{cite journal |last1=Xu |first1=Peirong |last2=Kirkland |first2=Earl J. |last3=Silcox |first3=John |last4=Keyse |first4=Robert |title=High-resolution imaging of silicon (111) using a 100 keV STEM |url=https://archive.org/details/sim_ultramicroscopy_1990-02_32_2/page/93 |journal=Ultramicroscopy |year=1990 |volume=32 |issue=2 |pages=93–102 |doi=10.1016/0304-3991(90)90027-J |doi-access=free}}</ref>。其中环形明场像（ABF）也可得到原子级分辨率的图像，其常用于诸如[[氧]]、[[锂]]等轻元素的观测<ref>{{cite journal |last1=Findlay |first1=S.D. |last2=Shibata |first2=N. |last3=Sawada |first3=H. |last4=Okunishi |first4=E. |last5=Kondo |first5=Y. |last6=Ikuhara |first6=Y. |title=Dynamics of annular bright field imaging in scanning transmission electron microscopy |journal=Ultramicroscopy |year=2010 |volume=32 |issue=7 |pages=903–923 |doi=10.1016/j.ultramic.2010.04.004 |pmid=20434265}}</ref><ref>{{Cite journal |author=S.D. Findlay, N. Shibata, H. Sawada, et al |title=Dynamics of annular bright field imaging in scanning transmission electron microscopy |journal=Ultramicroscopy |language=en |year=2010 |volume=110 |issue=7 |page=903-923 |doi=10.1016/j.ultramic.2010.04.004}}</ref>。在同样成像条件下，ABF像分辨率比ADF像高，但ABF更容易受像差影响<ref name=":4">{{Cite journal |author=贾志宏，丁立鹏，陈厚文 |title=高分辨扫描透射电子显微镜原理及其应用 |journal=物理 |language=zh-cn |year=2015 |volume=7 |page=446-452 |doi=10.7693/wl20150704}}</ref>[[File:Scanning transmission electron microscopy srtio3 compare adf abf.jpg|thumb|[[钛酸锶|SrTiO<sub>3</sub>]]的原子级分辨率的环形暗场像（左）和环形明场像（右）示意图。插图：SrTiO<sub>3</sub>的晶格示意图，绿色：[[锶|Sr]]，灰色：[[钛|Ti]]，红色：[[氧|O]]|none|180x180px]]

=== 微分相位衬度成像（DPC） ===
[[File:Stem_dpc_schematic_magnetic_explanation.jpg|thumb|150x150px|微分相位衬度成像示意图，其中电子束在材料中局部磁场作用下发生偏转。]]
'''微分相位衬度成像'''或'''差分相位衬度成像'''是利用电磁场对电子束进行偏转成像的模式。运动的电子受到[[洛伦兹力]]作用下会发生偏转，当带有一个负电荷-[[基本电荷|e]]的电子穿过电场'''<math>E</math>'''和[[磁場|磁场]]'''<math>B</math>'''时受到的力'''<math>F</math>'''为：

<math>\mathbf{F} = -e\mathbf{E} - e\mathbf{v} \times \mathbf{B}</math>，其中<math>-e\mathbf{E}</math>为电子受电场产生的电场力，<math>- e\mathbf{v} \times \mathbf{B}</math>为受磁场产生的洛伦兹力。

对于纯磁场，电子束的偏转量{{math|''β''{{sub|L}}}}为<ref name="krajnak2016">{{cite journal |last1=Krajnak |first1=Matus |last2=McGrouther |first2=Damien |last3=Maneuski |first3=Dzmitry |last4=Shea |first4=Val O' |last5=McVitie |first5=Stephen |title=Pixelated detectors and improved efficiency for magnetic imaging in STEM differential phase contrast |journal=Ultramicroscopy |date=June 2016 |volume=165 |pages=42–50 |doi=10.1016/j.ultramic.2016.03.006 |pmid=27085170 |doi-access=free}}</ref>:

: <math>\beta_L = -\frac{e\lambda}{h} \int \mathbf{B} \times d\mathbf{l}</math>

[[File:Ferromagnetic_domains_in_spiral_pattern_for_Fe60Al40.jpg|thumb|150x150px|Fe<sub>60</sub>Al<sub>40</sub>的STEM-DPC图像，图中彩色螺旋区域代表铁磁性区域，其他区域为非磁性区域。]]
其中<math>\lambda</math>为电子波长，<math>h</math>为[[普朗克常数]]，<math>\textstyle\int \mathbf{B} \times d\mathbf{l}</math>为电子在磁场中沿偏转轨迹累计受到的磁感应强度。

若电子以垂直于厚度为<math>t</math>的样品入射，且样品中对应局部区域内部磁感应强度恒定为<math>B_S</math>，则<math>\textstyle\int \mathbf{B} \times d\mathbf{l}</math>可简化为一个常数<math> B_S t</math>，因此可以通过分段扫描或采用阵列检测器收集偏转电子束可以得到DPC像<ref name="krajnak2016" />。基于该原理，可以对材料内部的电场<ref>{{cite journal |last1=Haas |first1=Benedikt |last2=Rouvière |first2=Jean-Luc |last3=Boureau |first3=Victor |last4=Berthier |first4=Remy |last5=Cooper |first5=David |title=Direct comparison of off-axis holography and differential phase contrast for the mapping of electric fields in semiconductors by transmission electron microscopy. |journal=Ultramicroscopy |date=March 2019 |volume=198 |pages=58–72 |doi=10.1016/j.ultramic.2018.12.003 |pmid=30660032 |s2cid=58636157 |doi-access=free}}</ref>和磁场<ref name="krajnak2016" /><ref>{{cite journal |last1=McVitie |first1=S. |last2=Hughes |first2=S. |last3=Fallon |first3=K. |last4=McFadzean |first4=S. |last5=McGrouther |first5=D. |last6=Krajnak |first6=M. |last7=Legrand |first7=W. |last8=Maccariello |first8=D. |last9=Collin |first9=S. |last10=Garcia |first10=K. |last11=Reyren |first11=N. |title=A transmission electron microscope study of Néel skyrmion magnetic textures in multilayer thin film systems with large interfacial chiral interaction |journal=Scientific Reports |date=9 April 2018 |volume=8 |issue=1 |pages=5703 |arxiv=1711.05552 |bibcode=2018NatSR...8.5703M |doi=10.1038/s41598-018-23799-0 |pmc=5890272 |pmid=29632330 |last12=Cros |first12=V. |last13=Fert |first13=A. |last14=Zeissler |first14=K. |last15=Marrows |first15=C. H.}}</ref>分布进行成像。

虽然洛伦兹力使电子束偏转的经典电磁模型能直观地解释DPC成像原理，但利用[[阿哈罗诺夫-玻姆效应]]解释由电磁场产生的相位移这一[[量子力学]]模型是不可忽视的<ref name="krajnak2016" />。

对于大多数[[铁磁性|铁磁材料]]来说，DPC模式下物磁透镜的电流大小需要减少到几乎为0。因为当铁磁性样品位于物镜磁场中时，样品内部磁场可高达几个[[特斯拉 (单位)|T]]，如此大的磁场可破坏大多数铁磁材料的[[磁畴]]结构<ref>{{cite journal |last1=Chapman |first1=J N |title=The investigation of magnetic domain structures in thin foils by electron microscopy |journal=Journal of Physics D: Applied Physics |date=14 April 1984 |volume=17 |issue=4 |pages=623–647 |doi=10.1088/0022-3727/17/4/003 |s2cid=250805904}}</ref>。然而，物镜电流的减小又会使得像差明显，电子束汇聚程度减弱，束斑变大，导致分辨率下降，因此需要一个像差校正器进行纠正，使得分辨率可达到1 nm量级<ref>{{cite journal |last1=McVitie |first1=S. |last2=McGrouther |first2=D. |last3=McFadzean |first3=S. |last4=MacLaren |first4=D.A. |last5=O’Shea |first5=K.J. |last6=Benitez |first6=M.J. |title=Aberration corrected Lorentz scanning transmission electron microscopy |url=http://eprints.gla.ac.uk/102200/2/102200.pdf |journal=Ultramicroscopy |date=May 2015 |volume=152 |pages=57–62 |doi=10.1016/j.ultramic.2015.01.003 |pmid=25677688 |access-date=2024-08-14 |archive-date=2024-04-12 |archive-url=https://web.archive.org/web/20240412020417/https://eprints.gla.ac.uk/102200/2/102200.pdf |dead-url=no }}</ref>。

=== 四维STEM（4D STEM） ===
4D STEM是一种新的STEM技术，其检测器可以记录样品扫描过程中每一个像素点处所有的散射和非-{zh-hans:散射电子; zh-hant:散射電子}-形成会聚束电子衍射图案，即形成一个4维的数据集（每个2D扫描点处产生一个2D的衍射图案）<ref>{{cite journal |last1=Tate |first1=Mark W. |last2=Purohit |first2=Prafull |last3=Chamberlain |first3=Darol |last4=Nguyen |first4=Kayla X. |last5=Hovden |first5=Robert |last6=Chang |first6=Celesta S. |last7=Deb |first7=Pratiti |last8=Turgut |first8=Emrah |last9=Heron |first9=John T. |last10=Schlom |first10=Darrell G. |last11=Ralph |first11=Daniel C. |title=High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy |journal=Microscopy and Microanalysis |year=2016 |volume=22 |issue=1 |pages=237–249 |arxiv=1511.03539 |bibcode=2016MiMic..22..237T |doi=10.1017/S1431927615015664 |pmid=26750260 |s2cid=5984477 |last12=Fuchs |first12=Gregory D. |last13=Shanks |first13=Katherine S. |last14=Philipp |first14=Hugh T. |last15=Muller |first15=David A. |last16=Gruner |first16=Sol M.}}</ref>，因此该技术常被称为'''四维STEM'''技术<ref>{{cite journal |last=Ophus |first=Colin |title=Four-Dimensional Scanning Transmission Electron Microscopy (4D-STEM): From Scanning Nanodiffraction to Ptychography and Beyond |journal=Microscopy and Microanalysis |language=en |date=June 2019 |volume=25 |issue=3 |pages=563–582 |bibcode=2019MiMic..25..563O |doi=10.1017/S1431927619000497 |issn=1431-9276 |pmid=31084643 |doi-access=free}}</ref><ref>{{cite journal |title=4D STEM with a direct electron detector |url=https://analyticalscience.wiley.com/do/10.1002/was.00010003 |language=en |access-date=2020-02-11 |website=Wiley Analytical Science |archive-date=2022-03-05 |archive-url=https://web.archive.org/web/20220305162710/https://analyticalscience.wiley.com/do/10.1002/was.00010003 |dead-url=no }}</ref>。用该技术生成的4维数据集经过分析处理可重建出与任何传统探测器几何结构相当的图像，并可以高空间分辨率反应样品中的各种场，包括应变场、电场等<ref>{{cite journal |last1=Ciston |first1=Jim |last2=Ophus |first2=Colin |last3=Ercius |first3=Peter |last4=Yang |first4=Hao |last5=Dos Reis |first5=Roberto |last6=Nelson |first6=Christopher T. |last7=Hsu |first7=Shang-Lin |last8=Gammer |first8=Christoph |last9=Özdöl |first9=Burak V. |last10=Deng |first10=Yu |last11=Minor |first11=Andrew |title=Multimodal Acquisition of Properties and Structure with Transmission Electron Reciprocal-space (MAPSTER) Microscopy |journal=Microscopy and Microanalysis |year=2016 |volume=22(S3) |issue=S3 |pages=1412–1413 |bibcode=2016MiMic..22S1412C |doi=10.1017/S143192761600790X |doi-access=free}}</ref>。同时该技术也可用于{{le|叠层成像|ptychography}}。

== STEM中的光谱学技术 ==
=== 电子能量损失谱 ===
{{Main|电子能量损失谱}}当电子束透过样品时，一些电子与样品相互作用会发生非弹性散射导致电子损失一部分能量。在电子能量损失谱（EELS）中，通过一个电子能谱仪测量电子损失的能量大小，从而识别[[等离子体]]和元素电离损失峰（电离边）等特征信息。EELS的能量精度足以观察到电离边的精细结构，意味着EELS可用于测定元素分布<ref name="Egerton">{{cite book|editor=Egerton,R.F.|title=Electron Energy-Loss Spectroscopy in the Electron Microscope|publisher=Springer|isbn=978-1-4419-9582-7|year=2011}}</ref>。STEM中EELS可以实现原子级分辨率元素光谱分布表征<ref>{{cite journal |last1=Mundy |first1=Julia A. |last2=Hikita |first2=Yasuyuki |last3=Hidaka |first3=Takeaki |last4=Yajima |first4=Takeaki |last5=Higuchi |first5=Takuya |last6=Hwang |first6=Harold Y. |last7=Muller |first7=David A. |last8=Kourkoutis |first8=Lena F. |title=Visualizing the interfacial evolution from charge compensation to metallic screening across the manganite metal–insulator transition |journal=Nature Communications |year=2014 |volume=5 |pages=3464 |bibcode=2014NatCo...5.3464M |doi=10.1038/ncomms4464 |pmid=24632721 |doi-access=free}}</ref>。在此基础上利用能量单色器可以实现EELS约10 m[[電子伏特|eV]]的精度，使得STEM可以测定[[振动谱线|振动光谱]]<ref>{{cite journal |last1=Krivanek |first1=Ondrej L. |author1-link= |last2=Lovejoy |first2=Tracy C. |last3=Dellby |first3=Niklas |last4=Aoki |first4=Toshihiro |last5=Carpenter |first5=R. W. |last6=Rez |first6=Peter |last7=Soignard |first7=Emmanuel |last8=Zhu |first8=Jiangtao |last9=Batson |first9=Philip E. |last10=Lagos |first10=Maureen J. |last11=Egerton |first11=Ray F. |title=Vibrational spectroscopy in the electron microscope |journal=Nature |year=2016 |volume=514 |issue=7521 |pages=209–212 |bibcode=2014Natur.514..209K |doi=10.1038/nature13870 |pmid=25297434 |s2cid=4467249 |last12=Crozier |first12=Peter A.}}</ref>。

=== 能量色散X射线谱 ===
{{Main|能量色散X射线谱}}当电子束透过样品时，高速电子会击飞样品原子的电子使之发生电离，并释放出[[特性輻射|特征X射线]]。能量色散X射线谱（EDX或EDS）则是利用X射线能谱仪测定这些特征X射线，来实现样品的元素分析以及元素分布的测定<ref>{{cite journal |author1=Friel, J.J. |author2=Lyman, C.E. |title=Tutorial Review: X-ray Mapping in Electron-Beam Instruments |journal=Microscopy and Microanalysis |year=2006 |volume=12 |issue=1 |pages=2–25 |bibcode=2006MiMic..12....2F |citeseerx=10.1.1.548.9845 |doi=10.1017/S1431927606060211 |pmid=17481338 |s2cid=135786852}}</ref>。传统STEM中的EDS检测器仅能覆盖很小的[[立體角|立体角]]，X射线检测效率很低。但现已有大立体角的检测器发明出来<ref>{{cite journal |last1=Zaluzec |first1=Nestor J. |title=Innovative Instrumentation for Analysis of Nanoparticles: The π Steradian Detector |journal=Microsc. Today |year=2009 |volume=17 |issue=4 |pages=56–59 |doi=10.1017/S1551929509000224 |s2cid=137645643 |doi-access=free}}</ref>， 同时现如今已经实现了原子级的EDS元素分布表征<ref>{{cite journal |last1=Chen |first1=Z. |last2=Weyland |first2=M. |last3=Sang |first3=X. |last4=Xu |first4=W. |last5=Dycus |first5=J.H. |last6=Lebeau |first6=J.M. |last7=d'Alfonso |first7=A.J. |last8=Allen |first8=L.J. |last9=Findlay |first9=S.D. |title=Quantitative atomic resolution elemental mapping via absolute-scale energy dispersive X-ray spectroscopy |journal=Ultramicroscopy |year=2016 |volume=168 |issue=4 |pages=7–16 |doi=10.1016/j.ultramic.2016.05.008 |pmid=27258645 |doi-access=free}}</ref>。

== 其他STEM技术 ==
采用一些专用的样品杆以及对显微镜进行改造，可以得到多种STEM附加技术，下面将介绍一些改造示例：

=== STEM断层成像 ===
{{Main|电子断层成像术}}'''STEM断层成像'''是指通过倾斜样品获得一系列二维投影像，然后利用这些二维投影像进行三维重构就可以得到样品内外部结构信息的方法<ref>{{cite journal |last1=Levin |first1=Barnaby D.A. |last2=Padgett |first2=Elliot |last3=Chen |first3=Chien-Chun |last4=Scott |first4=M.C. |last5=Xu |first5=Rui |last6=Theis |first6=Wolfgang |last7=Jiang |first7=Yi |last8=Yang |first8=Yongsoo |last9=Ophus |first9=Colin |last10=Zhang |first10=Haitao |last11=Ha |first11=Don-Hyung |title=Nanomaterial datasets to advance tomography in scanning transmission electron microscopy |journal=Scientific Data |year=2016 |volume=3 |issue=160041 |page=160041 |arxiv=1606.02938 |bibcode=2016NatSD...360041L |doi=10.1038/sdata.2016.41 |pmc=4896123 |pmid=27272459 |last12=Wang |first12=Deli |last13=Yu |first13=Yingchao |last14=Abruña |first14=Hector D. |last15=Robinson |first15=Richard D. |last16=Ercius |first16=Peter |last17=Kourkoutis |first17=Lena F. |last18=Miao |first18=Jianwei |last19=Muller |first19=David A. |last20=Hovden |first20=Robert}}</ref> 。特别是对于高角环形暗场-STEM（HADDF-STEM）成像模式特别有用，因为HAADF-STEM像仅与样品质量投影厚度和原子序数大小有关，使得三维重构过程不用引入其他干扰，得到的三维图像高度可信<ref>{{cite journal |last1=Midgley |first1=P. A. |last2=Weyland |first2=M. |title=3D electron microscopy in the physical sciences: The development of Z-contrast and EFTEM tomography |journal=Ultramicroscopy |year=2003 |volume=96 |issue=3–4 |pages=413–431 |doi=10.1016/S0304-3991(03)00105-0 |pmid=12871805 |authorlink=Paul Midgley}}</ref>。

=== 冷冻STEM ===
[[低温电子显微镜|冷冻电镜]]技术与STEM技术结合得到的'''冷冻STEM'''（Cryo-STEM）技术允许样品在[[液氮]]或[[液氦]]温度下保持在显微镜中，这对于在室温高真空条件下易挥发的样品进行成像非常有用。如[[玻璃化]]的生物样品<ref>{{cite journal |last1=Wolf |first1=Sharon Grayer |last2=Houben |first2=Lothar |last3=Elbaum |first3=Michael |title=Cryo-scanning transmission electron tomography of vitrified cells |journal=Nature Methods |year=2014 |volume=11 |issue=4 |pages=423–428 |doi=10.1038/nmeth.2842 |pmid=24531421 |s2cid=5336785}}</ref>、玻璃化材料固液界面<ref>{{cite journal |last1=Zachman |first1=Michael J. |last2=Asenath-Smith |first2=Emily |last3=Estroff |first3=Lara A. |last4=Kourkoutis |first4=Lena F. |title=Site-Specific Preparation of Intact Solid–Liquid Interfaces by Label-Free In Situ Localization and Cryo-Focused Ion Beam Lift-Out |journal=Microscopy and Microanalysis |year=2016 |volume=22 |issue=6 |pages=1338–1349 |bibcode=2016MiMic..22.1338Z |doi=10.1017/S1431927616011892 |pmid=27869059 |s2cid=25314940 |doi-access=free}}</ref>以及含硫样品（室温电镜中硫容易升华）的观测都用到了冷冻STEM<ref>{{cite journal |last1=Levin |first1=Barnaby D.A. |last2=Zachman |first2=Michael J. |last3=Werner |first3=Jörg G. |last4=Sahore |first4=Ritu |last5=Nguyen |first5=Kayla X. |last6=Han |first6=Yimo |last7=Xie |first7=Baoquan |last8=Ma |first8=Lin |last9=Archer |first9=Lynden A. |last10=Giannelis |first10=Emmanuel P. |last11=Wiesner |first11=Ulrich |title=Characterization of Sulfur and Nanostructured Sulfur Battery Cathodes in Electron Microscopy Without Sublimation Artifacts |url=https://zenodo.org/record/889883 |journal=Microscopy and Microanalysis |year=2017 |volume=23 |issue=1 |pages=155–162 |bibcode=2017MiMic..23..155L |doi=10.1017/S1431927617000058 |pmid=28228169 |s2cid=6801783 |last12=Kourkoutis |first12=Lena F. |last13=Muller |first13=David A. |access-date=2024-08-14 |archive-date=2023-04-28 |archive-url=https://web.archive.org/web/20230428192053/https://zenodo.org/record/889883 |dead-url=no }}</ref>。

=== 原位/环境STEM ===
为了研究粒子在气相环境中的反应过程，可在STEM的样品室配置一个压差系统使得样品置于气流中反应，并配有一个特制的控温支架来调节反应温度<ref>{{cite journal |last1=Boyes |first1=Edward D. |last2=Ward |first2=Michael R. |last3=Lari |first3=Leonardo |last4=Gai |first4=Pratibha L. |title=ESTEM imaging of single atoms under controlled temperature and gas environment conditions in catalyst reaction studies |journal=Annalen der Physik |year=2013 |volume=525 |issue=6 |pages=423–429 |bibcode=2013AnP...525..423B |doi=10.1002/andp.201300068 |s2cid=119973907}}</ref>；亦或者改造成一个封闭的样品室并让气体在室内流动<ref>{{cite journal |last1=Li |first1=Y. |last2=Zakharov |first2=D. |last3=Zhao |first3=S. |last4=Tappero |first4=R. |last5=Jung |first5=U. |last6=Elsen |first6=A. |last7=Baumann |first7=Ph. |last8=Nuzzo |first8=R.G. |last9=Stach |first9=E.A. |last10=Frenkel |first10=A.I. |title=Complex structural dynamics of nanocatalysts revealed in Operando conditions by correlated imaging and spectroscopy probes |journal=Nature Communications |year=2015 |volume=6 |page=7583 |bibcode=2015NatCo...6.7583L |doi=10.1038/ncomms8583 |pmc=4491830 |pmid=26119246}}</ref>，这样就得到了'''原位STEM'''（in situ STEM）或'''环境STEM'''（ESTEM）。类似地，在STEM样品架上安装一个[[微流控]]封壳就得到了液相电子显微镜<ref>{{cite journal |last1=de Jonge |first1=N. |last2=Peckys |first2=D.B. |last3=Kremers |first3=G.J. |last4=Piston |first4=D.W. |title=Electron microscopy of whole cells in liquid with nanometer resolution |journal=Proceedings of the National Academy of Sciences of the USA |date=2009 |volume=106 |issue=7 |pages=2159–2164 |bibcode=2009PNAS..106.2159J |doi=10.1073/pnas.0809567106 |pmc=2650183 |pmid=19164524 |doi-access=free}}</ref><ref>{{cite journal |last1=Ievlev |first1=Anton V. |last2=Jesse |first2=Stephen |last3=Cochell |first3=Thomas J. |last4=Unocic |first4=Raymond R. |last5=Protopopescu |first5=Vladimir A. |last6=Kalinin |first6=Sergei V. |title=Quantitative Description of Crystal Nucleation and Growth from in Situ Liquid Scanning Transmission Electron Microscopy |journal=ACS Nano |year=2015 |volume=9 |issue=12 |pages=11784–11791 |doi=10.1021/acsnano.5b03720 |pmid=26509714}}</ref><ref>{{cite journal |last1=Unocic |first1=Raymond R. |last2=Lupini |first2=Andrew R. |last3=Borisevich |first3=Albina Y. |last4=Cullen |first4=David A. |last5=Kalinin |first5=Sergei V. |last6=Jesse |first6=Stephen |title=Direct-write liquid phase transformations with a scanning transmission electron microscope |journal=Nanoscale |year=2016 |volume=8 |issue=34 |pages=15581–15588 |doi=10.1039/C6NR04994J |osti=1333640 |pmid=27510435}}</ref>，可以用于研究纳米颗粒以及生物细胞在液体环境中的行为<ref>{{cite journal |last1=de Jonge |first1=N. |last2=Ross |first2=F.M. |title=Electron microscopy of specimens in liquid |url=https://www.researchgate.net/publication/51735636 |journal=Nature Nanotechnology |date=2011 |volume=6 |issue=8 |pages=695–704 |bibcode=2003NatMa...2..532W |doi=10.1038/nmat944 |pmid=12872162 |s2cid=21379512}}</ref>。

=== 低电压STEM ===
'''低压电子显微镜'''（LVEM） 是一种加速电压被设计为0.5-30 kV之间，即加速电压相对一般电镜较低的电子显微镜。而且有些LVEM设备同时也可具备[[扫描电子显微镜|扫描电镜]]（SEM）、[[透射电子显微镜|透射电镜]]（TEM）和扫描透射电镜（STEM）的功能。较低的加速电压可以增加图像衬度，这对生物标本来说特别重要，因为可以减少或免于试样的染色步骤（一般生物样品的电镜观测需要提前进行染色）。在LVEM的SEM、TEM和STEM模式下可以实现几纳米的分辨率，而且低加速电压使得电镜可以采用永磁体作为透镜，而且微柱可免于冷却<ref>{{cite journal |last=Nebesářová |first=Jana |author2=Vancová, Marie |title=How to Observe Small Biological Objects in Low-Voltage Electron Microscope |url=https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/div-classtitlehow-to-observe-small-biological-objects-in-low-voltage-electron-microscopediv/9A089B9CA06B9F5D18A2CD12EA4B2A24 |journal=Microscopy and Microanalysis |year=2007 |volume=13 |issue=S03 |pages=248–249 |bibcode=2007MiMic..13S.248N |doi=10.1017/S143192760708124X |s2cid=138891812 |access-date=2024-08-15 |archive-date=2018-10-23 |archive-url=https://web.archive.org/web/20181023081644/https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/div-classtitlehow-to-observe-small-biological-objects-in-low-voltage-electron-microscopediv/9A089B9CA06B9F5D18A2CD12EA4B2A24 |dead-url=no }}</ref><ref>{{cite journal |last=Drummy |first=Lawrence, F. |author2=Yang, Junyan |author3=Martin, David C. |title=Low-voltage electron microscopy of polymer and organic molecular thin films |journal=Ultramicroscopy |year=2004 |volume=99 |issue=4 |pages=247–256 |doi=10.1016/j.ultramic.2004.01.011 |pmid=15149719}}</ref>。

== 参见 ==
* [[电子衍射]]
* [[扫描电子显微镜]]
* [[穿透式電子顯微鏡]]

==参考文献==
{{reflist|30em}}

{{电子显微镜}}
[[Category:电子束]]
[[Category:电子显微术]]