Observations of a three-phase structure in high-modulus PAN-based carbon fibres

1973 ◽  
Vol 8 (2) ◽  
pp. 286-290 ◽  
Author(s):  
D. J. Johnson ◽  
D. Crawford ◽  
B. F. Jones
1999 ◽  
Vol 55 (2) ◽  
pp. 188-196 ◽  
Author(s):  
R. Høier ◽  
C. R. Birkeland ◽  
R. Holmestad ◽  
K Marthinsen

Quantitative convergent-beam electron diffraction is used to determine structure factors and three-phase structure invariants. The refinements are based on centre-disc intensities only. An algorithm for parameter-sensitive pixel sampling of experimental intensities is implemented in the refinement procedure to increase sensitivity and computer speed. Typical three-beam effects are illustrated for the centrosymmetric case. The modified refinement method is applied to determine amplitudes and three-phase structure invariants in noncentrosymmetric InP. The accuracy of the results is shown to depend on the choice of the initial parameters in the refinement. Even unrealistic starting assumptions and incorrect temperature factor lead to stable results for the structure invariant. The examples show that the accuracy varies from 1 to 10° in the electron three-phase invariants determined and from 0.5 to 5% for the amplitudes. Individual phases could not be determined in the present case owing to spatial intensity correlations between phase-sensitive pixels. However, for the three-phase structure invariant, stable solutions were found.


2021 ◽  
Vol 274 ◽  
pp. 107267
Author(s):  
Xin Zhang ◽  
Wanyin Qiu ◽  
Xiuyang Jiang ◽  
Hsun-Ming Hu ◽  
Haiyan Xiao ◽  
...  

Carbon ◽  
1976 ◽  
Vol 14 (5) ◽  
pp. 300
Author(s):  
P.G. Rose
Keyword(s):  

1992 ◽  
Vol 23 (3) ◽  
pp. 145-149
Author(s):  
M. T. Azarova

2013 ◽  
Vol 3 (0) ◽  
Author(s):  
Štefan Kavecký ◽  
Pavol Štefánik ◽  
Miroslav Hnatko ◽  
Marián Janek

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