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Electron Microscopy Solutions
Transmission Electron Microscopes

Themis Z for Materials Science

The ultimate in optical performance, reproducibility and flexibility.

In order for scientists to advance their understanding of complex materials and develop innovative new materials, they must be able to correlate form and function, resolve in space, time and frequency and investigate with robust, precise instrumentation.

Thermo Fisher Scientific introduces Themis Z – the next generation, ultra-high resolution, aberration corrected, scanning transmission electron microscope delivering the ultimate optical performance and flexibility with unprecedented reproducibility.

 





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The Ultimate in Optical Performance

Building on the Thermo Scientific™ proven CS corrected, stable Themis design, Themis Z delivers unparalleled imaging capability at atomic resolution in both high resolution TEM and STEM across the entire acceleration voltage range of 30 to 300 kilovolts.

STEM performance

The Themis Z delivers impressive STEM resolution down to <63 pm with wide gap S-TWIN pole pieces at 300 kV. The images show GaN [211] imaged at 300 kV and Si [110] imaged at 60 kV. The corresponding FFT's of GaN [211] and Si [110] clearly show dumbell resolution of 63 and 136 pm.

TEM performance

Atomic resolution imaging of an Au nanoparticle across the entire accelerating voltage range (from left to right: 300, 200 and 80 kV). 

Reproducibility

Not only is this capability cutting edge, it is also widely accessible.  

OptiSTEM+

Themis Z delivers tuning automation of the probe forming optics in STEM experiments with OptiSTEM+. This puts the ultimate spatial resolution and high experimental reproducibility at the fingertips of not only microscope experts but all materials scientists. 

OptiMONO

The automation theme continues on ThemisZ with OptiMono, which automatically aligns and optimizes the monochromator optics to again deliver the ultimate energy resolution with high experimental precision and reproducibility. The result is access to ultra-high resolution electron energy loss spectroscopy experiments which provides valuable chemical bonding information at atomic resolution for all materials scientists.

 

Flexibility

In order to advance our understanding of complex nano-materials, a tool is required that can deliver the ultimate performance regardless of the imaging or spectroscopic mode demanded by the specimen or research direction. A tool built to measure properties on the atomic scale should promise repeatability, accuracy and precision with no compromise. Innovation requires the freedom to explore and investigate without being limited by technology.

ThemisZ offers the flexibility to do just that.

Imaging flexibility with Themis Z

Knock-on damage on sensitive materials 

Dose sensitive materials 

Materials with low atomic number (Z)

MoS2 imaged at 30kV with monochromator ON.

Zeolite imaged at 300kV and <1pA with iDPC. Oxygen atoms are visible with extreme low doses. 

GaN [211] imaged at 300 kV with iDPC at 63 pm resolution (inset shows HAADF image). Ga and N dumbells are clearly visible. Imaging with iDPC allows simultaneous observation of light and heavy elements.

Imaging Magnetic Materials

Mapping field strength and direction with DPC in ferrite using the Electron Microscope Pixel Array Detector (EMPAD). Sample Courtesy: H. Nakajima and S. Mori, Osaka Prefecture University.

Choice of Super X or Dual X EDS detectors

 

The Therrmo Scientific EDS detector portfolio provides customers with a choice of detector geometries to suit their experimental requirements and optimize their EDS results.

Fast and accurate quantification is now also possible for both detector geometries with Thermo Scientific Velox™ analytical software.  

Energy Resolution to suit all EELS applications

ADF

Core loss EELS atomic resolution elemental map of BaTiO3/SrTiO3 interface. Ba in blue, Sr in red and Ti in green. Imaged at 80 kV (60 pA) with a 1 eV FWHM electron probe (49x49 pixels <90 seconds).

In this example, measurement of an area of Gold nanowire shows the localized position of plasmon excitations along the nanowires as a function of their excitation energy in the range of 0.18 eV to 1.2 eV. A monochromated electron probe with < 0.2 eV FWHM is required for those experiments.



Mapping of surface phonon modes in a MgO crystal at 60 kV using a monochromated electron probe with a FWHM <30 meV. Specimen and analysis, courtesy of Isobel Bicket and Prof. Gianluigi Botton, The Canadian Centre for Electron Microscopy, McMaster University.

"Lab in the Gap" in-situ Experiments

Themis Z offers the flexibility of accepting a wide range of holders for in situ experiments in its 'all-in-one' S-TWIN wide gap pole piece. The Thermo Scientific™ NanoEx holder family can be seamlessly integrated with the microscope, enabling MEMS device based heating  for atomic imaging at elevated temperatures. Here, gold nanoparticles are heated to 700 degrees Celcius and the resulting motion is captured simultaneously with full frame 4k by 4k pixel resolution at a rate of faster than 30 frames per second on the Thermo Scientific Ceta camera with speed enhancement. The results is high spatial and temporal resolution of a highly dynamic activity.

Documents

Themis Z Datasheet

Low damage, high sensitivity imaging and analysis of materials in 2D, 3D and 4D. Themis Z delivers it all at the highest resolutions with a single objective lens configuration.

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Publication list for Themis Z for Materials Science

Title: Multiscale differential phase contrast analysis with a unitary detector
Authors: Sergei Lopatin, Yurii P. Ivanov, Jurgen Kosel, Andrey Chuvilin
References:   Ultramicroscopy, Volume 162, March 2016, Pages 74-81  
DOI10.1016/j.ultramic.2015.12.008
Date: December 2015
Abstract
Title: Multiscale differential phase contrast analysis with a unitary detector
Authors: Sergei Lopatin, Yurii P. Ivanov, Jurgen Kosel, Andrey Chuvilin
References:   Ultramicroscopy, Volume 162, March 2016, Pages 74-81  
DOI10.1016/j.ultramic.2015.12.008
Date: December 2015
Abstract: A new approach to generate differential phase contrast (DPC) images for the visualization and quantification of local magnetic fields in a wide range of modern nano materials is reported. In contrast to conventional DPC methods our technique utilizes the idea of a unitary detector under bright field conditions, making it immediately usable by a majority of modern transmission electron microscopes. The approach is put on test to characterize the local magnetization of cylindrical nanowires and their 3D ordered arrays, revealing high sensitivity of our method in a combination with nanometer-scale spatial resolution.
Title: 3D structure of individual nanocrystals in solution by electron microscopy
Authors: Jungwon Park, Hans Elmlund, Peter Ercius, Jong Min Yuk, David T. Limmer, Qian Chen, Kwanpyo Kim, Sang Hoon Han, David A. Weitz, A. Zettl, A. Paul Alivisatos
References:   Science, Vol. 349, Issue 6245, pp. 290-295  
DOI10.1126/science.aab1343
Date: July 2015
Abstract
Title: 3D structure of individual nanocrystals in solution by electron microscopy
Authors: Jungwon Park, Hans Elmlund, Peter Ercius, Jong Min Yuk, David T. Limmer, Qian Chen, Kwanpyo Kim, Sang Hoon Han, David A. Weitz, A. Zettl, A. Paul Alivisatos
References:   Science, Vol. 349, Issue 6245, pp. 290-295  
DOI10.1126/science.aab1343
Date: July 2015
Abstract: Knowledge about the synthesis, growth mechanisms, and physical properties of colloidal nanoparticles has been limited by technical impediments. We introduce a method for determining three-dimensional (3D) structures of individual nanoparticles in solution. We combine a graphene liquid cell, high-resolution transmission electron microscopy, a direct electron detector, and an algorithm for single-particle 3D reconstruction originally developed for analysis of biological molecules. This method yielded two 3D structures of individual platinum nanocrystals at near-atomic resolution. Because our method derives the 3D structure from images of individual nanoparticles rotating freely in solution, it enables the analysis of heterogeneous populations of potentially unordered nanoparticles that are synthesized in solution, thereby providing a means to understand the structure and stability of defects at the nanoscale.
Title: Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting
Authors: A. De Backer, G.T. Martinez, K.E. MacArthur, L. Jones, A. Béché, P.D. Nellist, S. Van Aert
References:   Ultramicroscopy, Volume 151, April 2015, Pages 56-61  
Date: April 2015
Abstract
Title: Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting
Authors: A. De Backer, G.T. Martinez, K.E. MacArthur, L. Jones, A. Béché, P.D. Nellist, S. Van Aert
References:   Ultramicroscopy, Volume 151, April 2015, Pages 56-61  
DOI10.1016/j.ultramic.2014.11.028
Date: April 2015
Abstract: Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations.
Title: Freestanding van der Waals Heterostructures of Graphene and Transition Metal Dichalcogenides
Authors: Amin Azizi, Sarah Eichfeld, Gayle Geschwind, Kehao Zhang, Bin Jian, Debangshu Mukherjee, Lorraine Hossain, Aleksander F. Piasecki, Bernd Kabius, Joshua A. Robinson, and Nasim Alem
References:   ACS Nano, 2015, 9 (5), pp 4882-4890  
Date: April 2015
Abstract
Title: Freestanding van der Waals Heterostructures of Graphene and Transition Metal Dichalcogenides
Authors: Amin Azizi, Sarah Eichfeld, Gayle Geschwind, Kehao Zhang, Bin Jian, Debangshu Mukherjee, Lorraine Hossain, Aleksander F. Piasecki, Bernd Kabius, Joshua A. Robinson, and Nasim Alem
References:   ACS Nano, 2015, 9 (5), pp 4882-4890  
DOI10.1021/acsnano.5b01677
Date: April 2015
Abstract: Vertical stacking of two-dimensional (2D) crystals has recently attracted substantial interest due to unique properties and potential applications they can introduce. However, little is known about their microstructure because fabrication of the 2D heterostructures on a rigid substrate limits one's ability to directly study their atomic and chemical structures using electron microscopy. This study demonstrates a unique approach to create atomically thin freestanding van der Waals heterostructures-WSe2/graphene and MoS2/graphene-as ideal model systems to investigate the nucleation and growth mechanisms in heterostructures. In this study, we use transmission electron microscopy (TEM) imaging and diffraction to show epitaxial growth of the freestanding WSe2/graphene heterostructure, while no epitaxy is maintained in the MoS2/graphene heterostructure. Ultra-high-resolution aberration-corrected scanning transmission electron microscopy (STEM) shows growth of monolayer WSe2 and MoS2 triangles on graphene membranes and reveals their edge morphology and crystallinity. Photoluminescence measurements indicate a significant quenching of the photoluminescence response for the transition metal dichalcogenides on freestanding graphene, compared to those on a rigid substrate, such as sapphire and epitaxial graphene. Using a combination of (S)TEM imaging and electron diffraction analysis, this study also reveals the significant role of defects on the heterostructure growth. The direct growth technique applied here enables us to investigate the heterostructure nucleation and growth mechanisms at the atomic level without sample handling and transfer. Importantly, this approach can be utilized to study a wide spectrum of van der Waals heterostructures.