scholarly journals Continuous description of the atomic structure of grain boundaries using dislocation and generalized-disclination density fields

2016 ◽  
Vol 77 ◽  
pp. 75-89 ◽  
Author(s):  
Xiao-Yu Sun ◽  
Vincent Taupin ◽  
Claude Fressengeas ◽  
Patrick Cordier
Author(s):  
H.W. Zandbergen ◽  
M.R. McCartney

Very few electron microscopy papers have been published on the atomic structure of the copper oxide based superconductor surfaces. Zandbergen et al. have reported that the surface of YBa2Cu3O7-δ was such that the terminating layer sequence is bulk-Y-CuO2-BaO-CuO-BaO, whereas the interruption at the grain boundaries is bulk-Y-CuO2-BaO-CuO. Bursill et al. reported that HREM images of the termination at the surface are in good agreement with calculated images with the same layer sequence as observed by Zandbergen et al. but with some oxygen deficiency in the two surface layers. In both studies only one or a few surfaces were studied.


Author(s):  
R. W. Fonda ◽  
D. E. Luzzi

The properties of polycrystalline materials are strongly dependant upon the strength of internal boundaries. Segregation of solute to the grain boundaries can adversely affect this strength. In copper alloys, segregation of either bismuth or antimony to the grain boundary will embrittle the alloy by facilitating intergranular fracture. Very small quantities of bismuth in copper have long been known to cause severe grain boundary embrittlement of the alloy. The effect of antimony is much less pronounced and is observed primarily at lower temperatures. Even though moderate amounts of antimony are fully soluble in copper, concentrations down to 0.14% can cause grain boundary embrittlement.


2004 ◽  
Vol 70 (12) ◽  
Author(s):  
Fumiyasu Oba ◽  
Hiromichi Ohta ◽  
Yukio Sato ◽  
Hideo Hosono ◽  
Takahisa Yamamoto ◽  
...  

2018 ◽  
Vol 31 (4) ◽  
pp. 1805047 ◽  
Author(s):  
Arashdeep Singh Thind ◽  
Guangfu Luo ◽  
Jordan A. Hachtel ◽  
Maria V. Morrell ◽  
Sung Beom Cho ◽  
...  

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Kalyanaraman ◽  
S. Oktyabrsky ◽  
K. Jagannadham ◽  
J. Narayan

AbstractThe atomic structure of grain boundaries in pulsed laser deposited YBCO/MgO thin films have been studied using transmission electron microscopy. The films have perfect texturing with YBCO(001)//MgO(001), giving rise to low-angle [001] tilt boundaries from the grains with the c-axis normal to substrate surface. Low angle grain boundaries have been found to be aligned preferentially along (100) and (110) interface planes. The energy of (110) boundary planes described by an alternating array of [100] and [010] dislocation is found to be comparable to the energy of a (100) boundary. The existence of these split dislocations is shown to further reduce the theoretical current densities of these boundaries indicating that (110) boundaries carry less current as compared to (100) boundaries of the same misorientation angle. Further, Z-contrast transmission electron microscopy of a 42° asymmetric high-angle grain boundary of YBCO shows evidence for the existence of boundary fragments and a reduced atomic density along the boundary plane


2001 ◽  
Vol 7 (S2) ◽  
pp. 244-245
Author(s):  
G.H. Campbell ◽  
W.E. King ◽  
J.M. Plitzko ◽  
J. Belak ◽  
S.M. Foiles

The technique of high-resolution transmission electron microscopy (HREM) produces images that contain information about the atomic structure of the specimen. Within additional, very stringent, constraints, the HREM image can contain information about atomic structure of crystal defects, including grain boundaries and interfaces. to extract this information from the image it is necessary to compare the experimental image with a simulated image calculated based upon an atomic model of the specimen.2 in this comparison, investigators have been aided by the use of quantitative techniques.Atomistic simulations are often used to predict the atomic structure of crystal defects or to simulate the evolution of dynamic processes in crystals, e.g. radiation effects or dislocation motion and interaction. During the development of new models of interatomic interactions, the predictions of simulations are tested against experimental observations to validate new potentials. Grain boundary structure is a good test because atoms residing in the boundary experience environments (interatomic distances and angles) that are significantly different from those experienced by atoms residing in a perfect crystal lattice site.


Materia Japan ◽  
1998 ◽  
Vol 37 (5) ◽  
pp. 364-364
Author(s):  
Takayuki Takasugi ◽  
Shuji Hanada ◽  
Kenji Hiraga

1995 ◽  
Vol 72 (3) ◽  
pp. 529-544 ◽  
Author(s):  
Fu-Rong Chen ◽  
Chia-Chi Chu ◽  
Jian-Yih Wang ◽  
Li Chang

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