Re: A question about stacking faults

[Andreas Leineweber]

The theory of line broadening due to stacking faults as presented in Warren's book has been improved recently further: X-ray diffraction analysis of stacking and twin faults in f.c.c. metals: a revision and allowance for texture and non-uniform fault probabilities VELTEROP L, DELHEZ R, DE KEIJSER TH, et al. JOURNAL OF APPLIED CRYSTALLOGRAPHY 33: 296-306 Part 2, APR 2000 and, with an even further development Estevez-Rams E, Leoni M, Scardi P, et al. On the powder diffraction pattern of crystals with stacking faults  PHILOSOPHICAL MAGAZINE 83 (36): 4045-4057 DEC 21 2003   I have not worked with these papers in detail, but I think the authors claimed that there were severe approximations made by Warren, and the changes are considerable. Best regards Andreas Leineweber ling yang wrote: Dear all,   Are there anybody experienced in stacking faults? Please help me! Basically I'm following Warren's book and R. Berliner's paper to simulate the possible effects of stacking faults on diffraction patterns. I did generate a set of patterns for fcc, but there are some questions I'm not clear:   1 What is the relation of (hkl) between the cubic fcc and the hexagonal lattice cell, for example, what does this (1 0 1/3) stand for in the orginal cubic cell? All those papers use the distance between layers as the c value, i.e., A=-a/2+b/2, B=-b/2+c/2, C=(a+b+c)/3, the original (111) plane will be (-1 1 3). I don't know what is this l=1/3 or 2/3 stand for.   2 Besides peak broadening and peak position shifting, are there other effects by the long-range one-dimensinal disorderness? Is it possible to get superlattice peaks which have bigger d-space than the original cell? Should I set a superlattice layer sequence first, e.g., the fcc sequence is ABCABC..., should i set a sequence like ABCDEFABCDEF... as a model for simulation, so that extra peaks will appear?   Please please help. Thanks greatly.   Sincerely,   Ling Yang Dept of CME, Univ of Cincinnati Current address: Bldg 8600, MS 6474 SNS, Oak Ridge National Laboratory Oak Ridge, TN 37830 Tel: 865 574 0350 Fax: 865 241 5177 -- Dr. Andreas Leineweber Max-Planck-Institut fuer Metallforschung Heisenbergstrasse 3 70569 Stuttgart Germany Telephone: +49 (0)711 689 3365 Telefax: +49 (0)711 689 3312 [EMAIL PROTECTED] http://www.mf.mpg.de/de/abteilungen/mittemeijer/english/index_english.htm