scholarly journals Enhanced Morphological and Thermal Stabilities of Nickel Germanide with an Ultrathin Tantalum Layer Studied by Ex Situ and In Situ Transmission Electron Microscopy

2013 ◽  
Vol 19 (S5) ◽  
pp. 114-118 ◽  
Author(s):  
Jae-Wook Lee ◽  
Hyung-Kyu Kim ◽  
Jee-Hwan Bae ◽  
Min-Ho Park ◽  
Hyoungsub Kim ◽  
...  

AbstractThe formation and morphological evolution of germanides formed in a ternary Ni/Ta-interlayer/Ge system were examined by ex situ and in situ annealing experiments. The Ni germanide film formed in the Ni/Ta-interlayer/Ge system maintained continuity up to 550°C, whereas agglomeration of the Ni germanide occurred in the Ni/Ge system without Ta-interlayer. Through microstructural and chemical analysis of the Ni/Ta-interlayer/Ge system during and after in situ annealing in a transmission electron microscope, it was confirmed that the Ta atoms remained uniformly on the top of the newly formed Ni germanide layer during the diffusion reaction. Consequently, the agglomeration of the Ni germanide film was retarded and the thermal stability was improved by the Ta incorporation.

Microscopy ◽  
2018 ◽  
Vol 67 (2) ◽  
pp. 112-120
Author(s):  
Hiroyasu Saka ◽  
Hiroyuki Iwata ◽  
Daisuke Kawaguchi

Abstract Radiation of a permeable laser beam into Si induces considerable modification of structures. Thermal stability of the laser-induced modified volumes (LIMV’s) was studied comprehensively by means of in situ and ex situ heating experiments using transmission electron microscopy. The behavior in the tail region of a LIMV can be understood by dislocation theory, while that of a void formed at the very focus of a laser beam cannot be understood easily.


2000 ◽  
Vol 652 ◽  
Author(s):  
D.L. Medlin ◽  
G. Lucadamo

ABSTRACTWe examine the morphological evolution of faceted grain boundaries in gold during annealing. Experiments were performed on <111> oriented gold films composed of two Σ=3 related orientation variants. The boundaries between these variants initially possess a high density of finely spaced (<25 nm) facets on {112} type planes. During annealing a large proportion of these fine-scale corrugations are annihilated, and the facet distribution coarsens significantly. Through in situ transmission electron microscopy (TEM), we directly observe this coarsening process. These results show a more complex behavior than geometric models for facet evolution would suggest and point to the need for an improved understanding of facet-junction properties and the interactions between grain boundary facets and dislocations.


1998 ◽  
Vol 4 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Maxim V. Sidorov ◽  
Beata Kardynal ◽  
David J. Smith

Morphological evolution associated with silicidation of Co thin films deposited on (100) and (111) Si substrates has been followed using transmission electron microscopy with in situ thermal annealing from ambient temperature up to 850°C. Noticeable structural changes associated with the formation of CoSi2 occur at temperatures as low as 400°C and the reaction is essentially complete at about 500°C. Prolonged heating above 500°C leads to CoSi2 grain growth and coalescence and, finally, to pinholes formation. Silicidation of Co films on (100) and (111) Si substrates follows the same pattern. The morphology of films annealed in situ is similar to those annealed ex situ except that the Si/CoSi2 interface appears to be much rougher. This behavior is associated with the specific geometry of cross-sectional TEM specimens, where surface diffusion dominates bulk diffusion. Very thin Co films, which have less contribution from surface diffusion than thicker films, are ideal for studying dynamic phenomena at Co/Si reactive interfaces.


Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.


NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850119
Author(s):  
Xiaoyan Li ◽  
Yunlong Yu ◽  
Xiangfeng Guan ◽  
Peihui Luo ◽  
Linqin Jiang ◽  
...  

Eu[Formula: see text]/Tb[Formula: see text] co-doped nanocomposite containing CeO2 nanocrystals was successfully prepared by an in situ sol–gel polymerization approach. High-resolution transmission electron microscopy demonstrated the homogeneous precipitation of CeO2 nanocrystals among the polymethylmethacrylate (PMMA) matrix. The thermal stability and UV-shielding capability of the obtained nanocomposite were improved with increase of CeO2 content. The tuning of the emissive color from green and yellow to red can be easily achieved by varying the dopant species and concentration. These results suggested that the obtained nanocomposite could be potentially applicable in transparent solid-state luminescent devices.


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