Quantification of electron–phonon scattering for determination of temperature variations at high spatial resolution in the transmission electron microscope

2012 ◽  
Vol 23 (20) ◽  
pp. 205705 ◽  
Author(s):  
Li He ◽  
Robert Hull
2013 ◽  
Vol 19 (S5) ◽  
pp. 58-61 ◽  
Author(s):  
Mino Yang ◽  
Jun-Ho Lee ◽  
Hee-Goo Kim ◽  
Euna Kim ◽  
Young-Nam Kwon ◽  
...  

AbstractDistribution of wax in laser printer toner was observed using an ultra-high-voltage (UHV) and a medium-voltage transmission electron microscope (TEM). As the radius of the wax spans a hundred to greater than a thousand nanometers, its three-dimensional recognition via TEM requires large depth of focus (DOF) for a volumetric specimen. A tomogram with a series of the captured images would allow the determination of their spatial distribution. In this study, bright-field (BF) images acquired with UHV-TEM at a high tilt angle prevented the construction of the tomogram. Conversely, the Z-contrast images acquired by the medium-voltage TEM produced a successful tomogram. The spatial resolution for both is discussed, illustrating that the image degradation was primarily caused by beam divergence of the Z-contrast image and the combination of DOF and chromatic aberration of the BF image from the UHV-TEM.


2020 ◽  
Vol 26 (1) ◽  
pp. 126-133
Author(s):  
Ming Li ◽  
Ruth Knibbe

AbstractMicrochip technology with electron transparent membranes is a key component for in situ liquid transmission electron microscope (TEM) characterization. The membranes can significantly influence the TEM imaging spatial resolution, not only due to introducing additional material layers but also due to the associated bulging. The membrane bulging is largely defined by the membrane materials, thickness, and short dimension. The impact of the membrane on the spatial resolution, especially the extent of its bulging, was systematically investigated through the impact on the signal-to-noise ratio, chromatic aberration, and beam broadening. The optimization of the membrane parameters is the key component when designing the in situ TEM liquid cell. The optimal membrane thickness of 50 nm was found which balances the impact of membrane bulging and membrane thickness. Beyond this, the short membrane window dimension and the chip nominal spacing should be minimized. However, these two parameters have practical limitations in regards to chip handling.


2016 ◽  
Vol 858 ◽  
pp. 269-273
Author(s):  
Anne Henry ◽  
Hiroshi Yano ◽  
Tomoaki Hatayama

The photoluminescence of the near band gap emission of 10H-SiC is revealed for the first time and detected just below 3.0 eV. The crystallinity thus polytype of the sample is controlled with transmission electron microscope analyses and Laue diffraction. On the photoluminescence spectra up to eight sharp lines are associated to the non-phonon lines of the nitrogen bound exciton even if ten are expected in 10H-SiC. Phonon replicas of these non-phonon lines are observed at lower energy with energy separations similar than those in other hexagonal SiC polytypes. At moderate temperature free-exciton replicas are also observed which allow the determination of the excitonic band gap at 3020.6 meV, value in agreement with the hexagonality of 10H-SiC of 40%. The binding energies associated to the nitrogen bound-excitons are determined as well as the ionization energies of the nitrogen donors in the 10H-SiC polytype.


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