Point defects in irradiated Li3VO4 single crystal

1995 ◽  
Vol 77 (6) ◽  
pp. 2339-2342 ◽  
Author(s):  
T. Miki ◽  
T. Murata ◽  
T. Ishii ◽  
Y. Ebina ◽  
S. Sakata ◽  
...  
Keyword(s):  
Single Crystal ◽  
Point Defects

Detection of a point defect in a silicon single crystal by high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 466-467
Author(s):  
M. Awaji
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Point Defect ◽  
Point Defects ◽  
Noise Level ◽  
Dark Field ◽  
Silicon Single Crystal ◽  
High Resolution Image ◽  
Dark Field Imaging ◽  
Field Imaging

It is necessary to improve the resolution, brightness and signal-to-noise ratio(s/n) for the detection and identification of point defects in crystals. In order to observe point defects, multi-beam dark-field imaging is one of the useful methods. Though this method can improve resolution and brightness compared with dark-field imaging by diffuse scattering, the problem of s/n still exists. In order to improve the exposure time due to the low intensity of the dark-field image and the low resolution, we discuss in this paper the bright-field high-resolution image and the corresponding subtracted image with reference to a changing noise level, and examine the possibility for in-situ observation, identification and detection of the movement of a point defect produced in the early stage of damage process by high energy electron bombardment.The high-resolution image contrast of a silicon single crystal in the [10] orientation containing a triple divacancy cluster is calculated using the Cowley-Moodie dynamical theory and for a changing gaussian noise level. This divacancy model was deduced from experimental results obtained by electron spin resonance. The calculation condition was for the lMeV Berkeley ARM operated at 800KeV.

The effect of correlated and point defects on the vortex lattice melting transition in single-crystal YBa2Cu3O7-δ

1994 ◽  
Vol 197 (1-4) ◽  
pp. 579-587 ◽  
Author(s):  
W.K. Kwok ◽  
J. Fendrich ◽  
S. Fleshler ◽  
U. Welp ◽  
J. Downey ◽  
...  
Keyword(s):  
Single Crystal ◽  
Point Defects ◽  
Vortex Lattice ◽  
Melting Transition ◽  
Vortex Lattice Melting

Investigations of Microwave Absorption in Insulating Dielectric Ionic Crystals Including the Role of Point Defects and Dislocations

1996 ◽  
Vol 430 ◽  
Author(s):  
Benjamin D.B. Klein ◽  
Binshen Meng ◽  
Samuel A. Freeman ◽  
John H. Booske ◽  
Reid F. Cooper
Keyword(s):  
Theoretical Model ◽  
Single Crystal ◽  
Microwave Absorption ◽  
Point Defects ◽  
Ionic Conduction ◽  
Cavity Resonator ◽  
Preparation Technique ◽  
Ionic Crystals ◽  
Free Case

AbstractA theoretical model of microwave absorption in linear dielectric (non-ferroelectric) ionic crystals that takes into account the presence of point defects was synthesized and verified using NaCl single crystals. In the next stage of this research, we will introduce a controlled density of dislocations into the single crystal NaCl samples and study the effect on the microwave absorption mechanisms (ionic conduction, dielectric relaxation and multi-phonon processes) both theoretically and experimentally. Qualitative outlines of this modified theory are presented. The loss factor ε’ has been measured in the dislocation-free case by a cavity resonator insertion technique and the experimental results are in good agreement with the theoretical model. We describe the sample preparation technique that will be used to produce a controlled dislocation density in single crystal samples that will also be studied in our cavity resonator insertion system.

scholarly journals Ab Initio Analysis on Stability of Point Defects in Plane-Stressed Si Single Crystal

2007 ◽  
Vol 73 (732) ◽  
pp. 965-971
Author(s):  
Yanbo WANG ◽  
Koji SUEOKA ◽  
Seiji SHIBA ◽  
Seishiro FUKUTANI
Keyword(s):  
Single Crystal ◽  
Ab Initio ◽  
Point Defects

Length-scale Effects in Cascade Damage Production in Iron

2008 ◽  
Vol 1125 ◽  
Author(s):  
R. E. Stoller ◽  
P. J. Kamenski ◽  
Yu. N. Osetsky
Keyword(s):  
Single Crystal ◽  
Point Defects ◽  
Interatomic Potential ◽  
Scale Effects ◽  
Atomic Displacement ◽  
Nanocrystalline Iron ◽  
Cooling Phase ◽  
Primary Damage ◽  
Dynamics Simulations ◽  
Cascade Damage

ABSTRACTMolecular dynamics simulations provide an atomistic description of the processes that control primary radiation damage formation in atomic displacement cascades. An extensive database of simulations describing cascade damage production in single crystal iron has been compiled using a modified version of the interatomic potential developed by Finnis and Sinclair. This same potential has been used to investigate primary damage formation in nanocrystalline iron in order to have a direct comparison with the single crystal results. A statistically significant number of simulations were carried out at cascade energies of 10 keV and 20 keV and temperatures of 100 and 600K to make this comparison. The results demonstrate a significant influence of nearby grain boundaries as a sink for mobile defects during the cascade cooling phase. This alters the residual primary damage that survives the cascade event. Compared to single crystal, substantially fewer interstitials survive in the nanograined iron, while the number of surviving vacancies is similar or slightly greater than the single crystal result. The fraction of the surviving interstitials contained in clusters is also reduced. The asymmetry in the survival of the two types of point defects is likely to alter damage accumulation at longer times.

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