The Elimination of Vacancy-Cluster Formation in Dislocation-Free Silicon Crystals

1971 ◽  
Vol 118 (11) ◽  
pp. 1851 ◽  
Author(s):  
A. J. R. de Kock
Keyword(s):  
Cluster Formation ◽  
Vacancy Cluster ◽  
Silicon Crystals ◽  
Free Silicon

Point Defect Interactions and Vacancy Cluster Formation in Alkali Halide Crystals

1992 ◽  
Vol 134 (2) ◽  
pp. 351-358 ◽  
Author(s):  
A. V. Gektin ◽  
V. Ya. Serebryanny ◽  
N. V. Shiran
Keyword(s):  
Point Defect ◽  
Alkali Halide ◽  
Cluster Formation ◽  
Vacancy Cluster ◽  
Defect Interactions ◽  
Alkali Halide Crystals

scholarly journals Molecular dynamics simulation of vacancy cluster formation in β- and α-Si3N4

2020 ◽  
Vol 178 ◽  
pp. 109632
Author(s):  
E. Adabifiroozjaei ◽  
S.S. Mofarah ◽  
H. Ma ◽  
Y. Jiang ◽  
M. Hussein N. Assadi ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Cluster Formation ◽  
Vacancy Cluster ◽  
Dynamics Simulation

scholarly journals Dopant-vacancy cluster formation in germanium

2010 ◽  
Vol 107 (7) ◽  
pp. 076102 ◽  
Author(s):  
A. Chroneos
Keyword(s):  
Cluster Formation ◽  
Vacancy Cluster

Effect of Alloy Composition & Helium ion-irradiation on the Mechanical Properties of Tungsten, Tungsten-Tantalum & Tungsten-Rhenium for Fusion Power Applications

2013 ◽  
Vol 1514 ◽  
pp. 99-104 ◽  
Author(s):  
Christian E. Beck ◽  
Steve G. Roberts ◽  
Philip D. Edmondson ◽  
David E. J. Armstrong
Keyword(s):  
Mechanical Properties ◽  
Alloy Composition ◽  
Ion Irradiation ◽  
Cluster Formation ◽  
Vacancy Cluster ◽  
Indentation Hardness ◽  
Fusion Power ◽  
Appreciable Difference ◽  
Alloy Content ◽  
Helium Ion

ABSTRACTModel alloys have been made of pure W and 1% & 5% W-Ta and W-Re. Indentation hardness and modulus data were obtained by nanoindentation to assess the effect of composition on mechanical properties. Results showed that both the Ta and Re compositions hardened with increasing alloy content, greater in the W-5%Ta composition which showed an increase of 1.03GPa (17%), compared to a 0.43GPa (7%) increase in W-5%Re. The samples also showed very small increases in modulus of ∼ 25GPa (6%) in both W-5%Re and W-5%Ta. The samples were implanted with 3000appm concentration of helium. All samples show a substantial increase in hardness of up to 107% in the case of pure W. An appreciable difference in modulus is also seen in all samples. Initial TEM work has shown no visible He bubbles, suggesting that the mechanical properties changes are due to He-vacancy cluster formation below the resolvable limit.

Effect of solute atom concentration on vacancy cluster formation in neutron-irradiated Ni alloys

2011 ◽  
Vol 417 (1-3) ◽  
pp. 963-967 ◽  
Author(s):  
Koichi Sato ◽  
Daiki Itoh ◽  
Toshimasa Yoshiie ◽  
Qiu Xu ◽  
Akihiro Taniguchi ◽  
...  
Keyword(s):  
Solute Atom ◽  
Cluster Formation ◽  
Vacancy Cluster ◽  
Atom Concentration ◽  
Ni Alloys

scholarly journals Effects of Vacancy Cluster Defects on Electrical and Thermodynamic Properties of Silicon Crystals

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Pei-Hsing Huang ◽  
Chi-Ming Lu
Keyword(s):  
Heat Capacity ◽  
Debye Temperature ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Vacancy Cluster ◽  
Temperature Limit ◽  
Phase Changes ◽  
Hexagonal Ring ◽  
High Temperature Limit ◽  
Silicon Crystals

A first-principle plane-wave pseudopotential method based on the density function theory (DFT) was employed to investigate the effects of vacancy cluster (VC) defects on the band structure and thermoelectric properties of silicon (Si) crystals. Simulation results showed that various VC defects changed the energy band and localized electron density distribution of Si crystals and caused the band gap to decrease with increasing VC size. The results can be ascribed to the formation of a defect level produced by the dangling bonds, floating bonds, or high-strain atoms surrounding the VC defects. The appearance of imaginary frequencies in the phonon spectrum of defective Si crystals indicates that the defect-region structure is dynamically unstable and demonstrates phase changes. The phonon dispersion relation and phonon density of state were also investigated using density functional perturbation theory. The obtained Debye temperatureθDfor a perfect Si crystal had a minimum value of 448 K atT= 42 K and a maximum value of 671 K at the high-temperature limit, which is consistent with the experimental results reported by Flubacher. Moreover, the Debye temperature decreased with increases in the VC size. VC defects had minimal effects on the heat capacity (Cv) value when temperatures were below 150 K. As the temperature was higher than 150 K, the heat capacity gradually increased with increasing temperature until it achieved a constant value of 11.8 cal/cell·K. The heat capacity significantly decreased as the VC size increased. For a 2 × 2 × 2 superlattice Si crystal containing a hexagonal ring VC (HRVC10), the heat capacity decreased by approximately 17%.

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