Re: understanding peak width broadening during LiOH growth
Now Topas has anisotropy built in the GUI version too. No script is needed. Peter Peter Y. Zavalij, PHD Director - X-ray Crystallographic Center University of Maryland, College Park, MD 20742 On Tue, Aug 2, 2022 at 9:16 AM Radovan Cerny wrote: > Dear Enyuan, > > > as Wojciech said, you have certainly the effect of stacking faults. LiOH > is a tetragonal structure and the layers are parallel with ab plane. It > means that the faulting has an effect on the reflections with l-index > non-zero. The faulting can be roughly understood as a size effect in the > direction of c-axis. From your WH plot it is evident that the reflections > 110 and 200 are not-affected while all the others with l non-zero are > affected. With increasing l-index, the effect is stronger. > > You can easily refine this anisotropy with many Rietveld programs. Maybe > somebody can provide a script for Topas for example or in Profex or > Fullprof such models may be available. > > > It stays to explain why the cycling of a battery introduce stacking faults > in LiOH. > > > Best regards > > > Radovan > > > Radovan Cerny > Laboratoire de Cristallographie > Université de Genève > 24, quai Ernest-Ansermet > CH-1211 Geneva 4, Switzerland > Phone : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08 > mailto : radovan.ce...@unige.ch > URL: http://www.unige.ch/sciences/crystal/cerny/rcerny.htm > > > -- > *De :* rietveld_l-requ...@ill.fr de la part > de wslawin...@chem.uw.edu.pl > *Envoyé :* mercredi, 20 juillet 2022 11:16 > *À :* rietveld_l-requ...@ill.fr > *Objet :* Re: understanding peak width broadening during LiOH growth > > > Dear Enyuan, > > LiOH is definitely a layered structure. In such kind of structures, it is > likely that extra anisotropic broadening can be caused by “stacking > faults”. In your case, peaks with mixed kh and l index are generally > broader than those 00l or hk0. > > It would require a detailed study but you can also look at my paper > > https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.6b02247 > > With best regards, > > Wojciech Slawinski > > wslawin...@chem.uw.edu.pl > > > > *From:* rietveld_l-requ...@ill.fr <> *On Behalf Of *Enyuan Hu > *Sent:* Wednesday, July 20, 2022 5:41 AM > *To:* RIETVELD_L Distribution List > *Subject:* understanding peak width broadening during LiOH growth > > > > Hi all, > > > > I am seeking help on understanding why peak broadens during LiOH crystal > development. > > > > Background: we have identified LiOH as a major component in the interphase > of batteries and we are trying to understand how it evolves. We obtained > the Williamson-Hall plot for the LiOH phase as shown below. Black: 1st cycle; > Red: 5th cycle; Green: 30th cycle. So the green one has obvious anisotropic > broadening and we found literature that suggests this is due to > pallet-shaped LiOH. But going from 1st cycle to 30th cycle (black to > green), the peak width is in general more broadened. We thought LiOH would > grow in size so the peaks should become more sharp. So this is sort of > against our expectations. Can such a phenomenon be explained by strain and > if so, can anyone provide comments or suggestions? Thank you! > > > > Regards > > Enyuan > > > > [image: image.png] > ++ > Please do NOT attach files to the whole list > > Send commands to eg: HELP as the subject with no body > text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++ > > ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
RE: understanding peak width broadening during LiOH growth
Dear Enyuan, as Wojciech said, you have certainly the effect of stacking faults. LiOH is a tetragonal structure and the layers are parallel with ab plane. It means that the faulting has an effect on the reflections with l-index non-zero. The faulting can be roughly understood as a size effect in the direction of c-axis. From your WH plot it is evident that the reflections 110 and 200 are not-affected while all the others with l non-zero are affected. With increasing l-index, the effect is stronger. You can easily refine this anisotropy with many Rietveld programs. Maybe somebody can provide a script for Topas for example or in Profex or Fullprof such models may be available. It stays to explain why the cycling of a battery introduce stacking faults in LiOH. Best regards Radovan Radovan Cerny Laboratoire de Cristallographie Université de Genève 24, quai Ernest-Ansermet CH-1211 Geneva 4, Switzerland Phone : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08 mailto : radovan.ce...@unige.ch<mailto:radovan.ce...@unige.ch> URL: http://www.unige.ch/sciences/crystal/cerny/rcerny.htm De : rietveld_l-requ...@ill.fr de la part de wslawin...@chem.uw.edu.pl Envoyé : mercredi, 20 juillet 2022 11:16 À : rietveld_l-requ...@ill.fr Objet : Re: understanding peak width broadening during LiOH growth Dear Enyuan, LiOH is definitely a layered structure. In such kind of structures, it is likely that extra anisotropic broadening can be caused by “stacking faults”. In your case, peaks with mixed kh and l index are generally broader than those 00l or hk0. It would require a detailed study but you can also look at my paper https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.6b02247 With best regards, Wojciech Slawinski wslawin...@chem.uw.edu.pl From: rietveld_l-requ...@ill.fr <> On Behalf Of Enyuan Hu Sent: Wednesday, July 20, 2022 5:41 AM To: RIETVELD_L Distribution List Subject: understanding peak width broadening during LiOH growth Hi all, I am seeking help on understanding why peak broadens during LiOH crystal development. Background: we have identified LiOH as a major component in the interphase of batteries and we are trying to understand how it evolves. We obtained the Williamson-Hall plot for the LiOH phase as shown below. Black: 1st cycle; Red: 5th cycle; Green: 30th cycle. So the green one has obvious anisotropic broadening and we found literature that suggests this is due to pallet-shaped LiOH. But going from 1st cycle to 30th cycle (black to green), the peak width is in general more broadened. We thought LiOH would grow in size so the peaks should become more sharp. So this is sort of against our expectations. Can such a phenomenon be explained by strain and if so, can anyone provide comments or suggestions? Thank you! Regards Enyuan [image.png] ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: understanding peak width broadening during LiOH growth
Dear Enyuan, LiOH is definitely a layered structure. In such kind of structures, it is likely that extra anisotropic broadening can be caused by “stacking faults”. In your case, peaks with mixed kh and l index are generally broader than those 00l or hk0. It would require a detailed study but you can also look at my paper https://pubs.acs.org/doi/full/10.1021/acs.inorgchem.6b02247 With best regards, Wojciech Slawinski wslawin...@chem.uw.edu.pl From: rietveld_l-requ...@ill.fr <> On Behalf Of Enyuan Hu Sent: Wednesday, July 20, 2022 5:41 AM To: RIETVELD_L Distribution List Subject: understanding peak width broadening during LiOH growth Hi all, I am seeking help on understanding why peak broadens during LiOH crystal development. Background: we have identified LiOH as a major component in the interphase of batteries and we are trying to understand how it evolves. We obtained the Williamson-Hall plot for the LiOH phase as shown below. Black: 1st cycle; Red: 5th cycle; Green: 30th cycle. So the green one has obvious anisotropic broadening and we found literature that suggests this is due to pallet-shaped LiOH. But going from 1st cycle to 30th cycle (black to green), the peak width is in general more broadened. We thought LiOH would grow in size so the peaks should become more sharp. So this is sort of against our expectations. Can such a phenomenon be explained by strain and if so, can anyone provide comments or suggestions? Thank you! Regards Enyuan ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++ ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
