Influence of exogenous xenon atoms on the evolution kinetics of extended defects in polycrystalline UO2 using in situ TEM

2018 ◽  
Vol 512 ◽  
pp. 297-306 ◽  
Author(s):  
C. Onofri ◽  
C. Sabathier ◽  
C. Baumier ◽  
C. Bachelet ◽  
H. Palancher ◽  
...  
Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).


2016 ◽  
Vol 22 (S3) ◽  
pp. 768-769 ◽  
Author(s):  
S. W. Sohn ◽  
Y. Jung ◽  
Y. Xie ◽  
C. Osuji ◽  
J. Schroers ◽  
...  

Nano Letters ◽  
2009 ◽  
Vol 9 (6) ◽  
pp. 2251-2254 ◽  
Author(s):  
Zhi Xu ◽  
Dmitri Golberg ◽  
Yoshio Bando

2001 ◽  
Vol 7 (S2) ◽  
pp. 408-409
Author(s):  
J. Lian ◽  
L. M. Wang ◽  
S. X. Wang ◽  
R. C. Ewing

The ion irradiation-induced crystalline-to-amorphous transformation has been studied in many complex ceramics. Direct impact amorphization has been considered to be one of the fundamental amorphization mechanisms for complex ceramics under heavy ion irradiation . Based on the directimpact model, a highly energetic incident ion transfers its kinetic energy to the target as a thermal spike within 10“13 sec creating a “molten-like” displacement cascade, typically nanometer-scaled in diameter (as indicated by the result of a computer simulation in Fig. 1). This “molten” zone quickly quenches to a small amorphous domain within a few pico-seconds. Epitaxial recrystallization occurs around the amorphous/crystalline interface, so that the size of amorphous domains decrease with time. The accumulation and overlap of small amorphous domains eventually leads to complete amorphization of the irradiated material. Although the in-situTEM technique with the setup shown in Fig. 2 has been extensively applied to the study of the amorphization process in complex ceramics, most of the previous studies relied on in-situobservation of the electron diffraction pattern, and there has been a lack of solid evidence of direct impact amorphization due to the small nature of the cascades and the rapid kinetics of its evolution.


Author(s):  
R. Anton ◽  
K. Heinemann

An in-situ study was performed of the growth kinetics of individual crystallites during the deposition of iron onto electron-transparent singlecrystalline α-Al2O3 (sapphire) substrates. Clean sapphire films were produced in-situ under UHV conditions by electron-beam induced crystallization of amorphous Al2O3 (1). Iron was electron-beam vapor-deposited at constant rates (0.2-0.5 nm/min) and elevated substrate temperatures (750 – 900°C) immediately following the crystallization. The nucleation, growth, and eventual coalescence of the metal particles were observed in-situ by transmission electron microscopy and recorded on video tape at 30 frames per second. In fig. 1, a growth and coalescence sequence of several Fe-particles on [100]-α-Al2O3 is shown. The images were selected and photographed from the TV monitor during video playback. The particles marked with letters were analyzed in detail. Noteworthy is that particle A (after about 30 min. of growth) started a rapid increase of its length-to-width ratio. Particle H, formed in a coalescence event, exhibited a preferred growth in a special direction, presumably in order to develop a certain crystallographic habit. Particle K developed a fast lateral growth ab-initio and remained a thin platelet until it coalesced with a neighboring particle about 25 min. after the beginning of the deposition.


2016 ◽  
Vol 482 ◽  
pp. 105-113 ◽  
Author(s):  
C. Onofri ◽  
C. Sabathier ◽  
C. Baumier ◽  
C. Bachelet ◽  
H. Palancher ◽  
...  
Keyword(s):  

1994 ◽  
Vol 337 ◽  
Author(s):  
Z. Atzmon ◽  
R. Sharma ◽  
S. W. Russell ◽  
J.W. Mayer

ABSTRACTCo-deposited Cu-Cr and Cu-Ti thin films were heated at various temperatures in an ammonia ambient in an environmental cell placed into the column of a transmission electron microscope (TEM). The reaction dynamics were observed in situ and recorded on a videotape using a TV camera with 1/30 second time resolution. Nitridation of chromium and titanium was accompanied by the nucleation and growth of copper particles starting at 370 and 580°C, respectively. It was found that in the Cu-Ti system at a temperatures regime of 370-400°C the growth rate behaves under a parabolic law; namely, the process is controlled by diffusion of Cu through the nitride matrix. However, for the Cu-Cr system at temperatures of 610-630°C two growth regimes were observed. In the initial growth stages, the surface reaction is rate-limiting, while for longer nitridation times, growth is diffusion-controlled.


2016 ◽  
Vol 36 (1) ◽  
pp. 31-38
Author(s):  
O. P. Kryshtal’ ◽  
◽  
S. I. Bogatyrenko ◽  
R. V. Sukhov ◽  
O. O. Minenkov ◽  
...  
Keyword(s):  

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