scholarly journals Calculations of energy band structure and mobility in critical bandgap strained Ge1-xSnx based on Sn component and biaxial tensile stress modulation

2018 ◽  
Vol 67 (2) ◽  
pp. 027101
Author(s):  
Di Lin-Jia ◽  
Dai Xian-Ying ◽  
Song Jian-Jun ◽  
Miao Dong-Ming ◽  
Zhao Tian-Long ◽  
...  
1967 ◽  
Vol 22 (2) ◽  
pp. 491-497 ◽  
Author(s):  
D. J. Morgan ◽  
J. A. Galloway

1997 ◽  
Vol 11 (11) ◽  
pp. 477-483 ◽  
Author(s):  
Z. J. Li ◽  
H. B. Xu ◽  
K. L. Yao

Starting from the extensional Su–Schrieffer–Heeger model taking into account the effects of interchain coupling, we have studied the energy spectra and electronic states of soliton excitation in polyacene. The dimerized displacement u0 is found to be similar to the case of trans-polyacetylene, and equals to 0.04 Å. The energy-band gap is 0.38 eV, in agreement with the results derived by other authors. Two new bound electronic states have been found in the conduction band and in the valence band, which is different from the one of trans-polyacetylene. There exists two degenerate soliton states in the center of energy gap. Furthermore, the distribution of charge density and spin density have been discussed in detail.


1975 ◽  
Vol 19 (3-4) ◽  
pp. 269-289 ◽  
Author(s):  
Chhi-Chong Wu ◽  
Jensan Tsai ◽  
Chung-Chan Wu

2021 ◽  
Vol 883 ◽  
pp. 303-308
Author(s):  
Peter Hetz ◽  
Matthias Lenzen ◽  
Martin Kraus ◽  
Marion Merklein

Numerical process design leads to cost and time savings in sheet metal forming processes. Therefore, a modeling of the material behavior is required to map the flow properties of sheet metal. For the identification of current yield criteria, the yield strength and the hardening behavior as well as the Lankford coefficients are taken into account. By considering the anisotropy as a function of rolling direction and stress state, the prediction quality of anisotropic materials is improved by a more accurate modeling of the yield locus curve. According to the current state of the art, the layer compression test is used to determine the corresponding Lankford coefficient for the biaxial tensile stress state. However, the test setup and the test procedure is quite challenging compared to other tests for the material characterization. Due to this, the test is only of limited suitability if only the Lankford coefficient has to be determined. In this contribution, a simplified test is presented. It is a reduction of the layer compression test to one single sheet layer. So the Lankford coefficient for the biaxial tensile stress state can be analyzed with a significantly lower test effort. The results prove the applicability of the proposed test for an easy and time efficient characterization of the biaxial Lankford coefficient.


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