what does it mean - "Fe sigma 3" symmetric tilt grain boundary ? I know about sigma. What is the plane and direction of the two grains and grain boundary ?
I need to know the unequivocal answer to this one. Gert! I confess I know not "Sigma". Point me in the right direction please. Some references, illustrations and examples with EBIC data would be wonderful. BTW know of any good 3D matrix relative intensity display software? Thanks Gert!
When does subgrain become grain boundary? It must have to do with the relative crystallographic misorientations of the neighboring regions in the perceived continuum of the "undistorted" monocrystal?
According to my understanding, sigma 3 describe a three dimensional coincidence site lattice (CSL), for Fe sigma 3" symmetric tilt grain boundary here, the coincidence site lattice is generated by rotation around axis by 70.5deg, i.e. let [1-11] lattice site in one crystal to coincident with [1 1 -1] lattice site in another lattice.
As for the boundary plane, sigma 3 does not tell you about the actual boundary plane, but it tells one what are the potential grain boundaries with high CSL sites, i.e. the interface prefer to pass high density of coincidence site in order to lower the boundary energy. For your case, it is the "symmetric tilt grain boundary", in usual convention the plane should be indicated. According to the CSL lattice on (110) plane( see attached figure, red points = lattice in crystal 1, blue = crystal 2, green points are coincidence lattice site), the possible "symmetric tilt grain boundary" is (1 -1 2) with highest CSL density or (1-1-1) with second highest CSL density. Therefore, the formal description should be like Σ3(1-1-1)[110] symmetric tilt grain boundary, Σ3(1-12)[110] symmetric tilt grain boundary.
Thanks a lot Dr. Xinfu Gu. I am looking for 'tilt angle' (from 0 to 90 degree) and corresponding 'crystallographic planes of the two grains' in iron symmetric tilt grain boundary. Where can I get them or how can I calculate them. Please help me.
good to know that at least Google knows, but you could at least change the word sequence...
http://www.tf.uni-kiel.de/matwis/amat/def_en/kap_7/backbone/r7_1_2.html
I read somewhere that the difference in youngsters today with the internet is that they may not know it all but know where to find the info quick to know it fast when needed! My kids (21, 26) are a prime example.
Thanks for all the posted information! Appreciate the effort to share!
BTW you may want to check this RG post about 2D real time Bragg XRD Microscopy, an in situ NDE tool, which is sensitive to fractions of ArcSec changes in the crystallographic orientation. The sample examined was the famous NIST 2000 SRM (STANDARD REFERENCE MATERIAL). Please post your critique/evaluation of the technique when convenient. We have employed XRR, (004) symmetric, (224) asymmetric and (113) asymmetric reflections. We've been able to successfully image the Nano structure of the wafer on both sides with a 27 um Pixel size 2D, 12/16 Bit device @ 12-13 fps (816x816 Pixels per frame) and a less than 2 kW X-ray generator.
https://www.researchgate.net/post/What_is_the_best_way_to_interpret_REAL_TIME_3D_X_Y_Omega_2Theta_reciprocal_space_relative_intensity_data_from_HRXRD_rocking_curve_analyses
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography