Pub Date : 2011-01-01DOI: 10.1524/9783486991321-024
A. Huq, J. P. Hodges, L. Heroux, O. Gourdon
Powgen represents a departure from previous designs for a time-of-flight powder diffractometer at a spallation neutron source and may be considered a third-generation design. The instrument is optimized for both parametric studies of materials under a wide range of conditions (T, P, H, flowing gases, etc) and ab-initio crystal structure determinations of complex solid-state materials with asymmetric unit-cells of the order {approx}1500 {angstrom}{sup 3}. The geometric design of the instrument allows for all detected scattered neutrons to be focused onto a single diffraction profile yielding high count rate while preserving good resolution {Delta}d/d = 0.0015 at a d = 1 {angstrom}.
{"title":"POWGEN: a third-generation high resolution high-throughput powder diffraction instrument at the Spallation Neutron Source","authors":"A. Huq, J. P. Hodges, L. Heroux, O. Gourdon","doi":"10.1524/9783486991321-024","DOIUrl":"https://doi.org/10.1524/9783486991321-024","url":null,"abstract":"Powgen represents a departure from previous designs for a time-of-flight powder diffractometer at a spallation neutron source and may be considered a third-generation design. The instrument is optimized for both parametric studies of materials under a wide range of conditions (T, P, H, flowing gases, etc) and ab-initio crystal structure determinations of complex solid-state materials with asymmetric unit-cells of the order {approx}1500 {angstrom}{sup 3}. The geometric design of the instrument allows for all detected scattered neutrons to be focused onto a single diffraction profile yielding high count rate while preserving good resolution {Delta}d/d = 0.0015 at a d = 1 {angstrom}.","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77392199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thin film Ni-Cu diffusion couples (individual layer thicknesses: 50 mn) have been prepared by direct-current magnetron sputtering on silicon substrates. The microstructural development and the stress evolution during diffusion annealing have been investigated employing ex-situ and in-situ X-ray diffraction, transmission electron microscopy and Auger-electron spectroscopy (in combination with sputter-depth profiling). Annealing at relatively low temperatures (175 degrees C to 350 degrees C) for durations up to about 100 hours results in considerable diffusional intermixing. In addition to thermal stresses due to mismatch of the coefficients of thermal expansion of layers and substrate, tensile stress contributions in the sublayers arise during diffusion anneals. The obtained stress data are discussed in terms of possible mechanisms of stress generation.
{"title":"Interdiffusion and stress development in Ni-Cu thin film diffusion couples","authors":"J. Sheng, U. Welzel, E. Mittemeijer","doi":"10.1524/zksu.2009.0036","DOIUrl":"https://doi.org/10.1524/zksu.2009.0036","url":null,"abstract":"Thin film Ni-Cu diffusion couples (individual layer thicknesses: 50 mn) have been prepared by direct-current magnetron sputtering on silicon substrates. The microstructural development and the stress evolution during diffusion annealing have been investigated employing ex-situ and in-situ X-ray diffraction, transmission electron microscopy and Auger-electron spectroscopy (in combination with sputter-depth profiling). Annealing at relatively low temperatures (175 degrees C to 350 degrees C) for durations up to about 100 hours results in considerable diffusional intermixing. In addition to thermal stresses due to mismatch of the coefficients of thermal expansion of layers and substrate, tensile stress contributions in the sublayers arise during diffusion anneals. The obtained stress data are discussed in terms of possible mechanisms of stress generation.","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84743385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Venter, C. P. L. Grange, F. Hofmann, T. Jun, J. Belnoue, P. R. V. Heerden, A. Evans, A. Korsunsky
{"title":"Synchrotron investigations of non-uniformly shaped shot-peened samples","authors":"A. Venter, C. P. L. Grange, F. Hofmann, T. Jun, J. Belnoue, P. R. V. Heerden, A. Evans, A. Korsunsky","doi":"10.1524/ZKSU.2009.0046","DOIUrl":"https://doi.org/10.1524/ZKSU.2009.0046","url":null,"abstract":"","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90835957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Macromolecular powder diffraction is a burgeoning technique for protein structure solution - ideally suited for cases where no suitable single crystals are available. Over the past seven years, pioneering work by Von Dreele et al. [1,2] and Margiolaki et al. [3,4] has demonstrated the viability of this approach for several protein structures. Among these initial powder studies, molecular replacement solutions of insulin and turkey lysozyme into alternate space groups were accomplished. Pressing the technique further, Margiolaki et al. [5] executed the first molecular replacement of an unknown protein structure: the SH3 domain of ponsin, using data from a multianalyzer diffractometer. To demonstrate that cross-species molecular replacement using image plate data is also possible, we present the solution of hen egg white lysozyme using the 60% identical human lysozyme (PDB code: 1LZ1) as the search model. Due to the high incidence of overlaps in powder patterns, especially in more complex structures, we have used extracted intensities from five data sets taken at different salt concentrations in a multi-pattern Pawley refinement. The use of image plates severely increases the overlap problem due to lower detector resolution, but radiation damage effects are minimized with shorter exposure times and the fact that the entiremore » pattern is obtained in a single exposure. This image plate solution establishes the robustness of powder molecular replacement resulting from different data collection techniques.« less
{"title":"Macromolecular powder diffraction : structure solution via molecular.","authors":"J. A. Doebbler, R. Dreele","doi":"10.1524/ZKSU.2009.0005","DOIUrl":"https://doi.org/10.1524/ZKSU.2009.0005","url":null,"abstract":"Macromolecular powder diffraction is a burgeoning technique for protein structure solution - ideally suited for cases where no suitable single crystals are available. Over the past seven years, pioneering work by Von Dreele et al. [1,2] and Margiolaki et al. [3,4] has demonstrated the viability of this approach for several protein structures. Among these initial powder studies, molecular replacement solutions of insulin and turkey lysozyme into alternate space groups were accomplished. Pressing the technique further, Margiolaki et al. [5] executed the first molecular replacement of an unknown protein structure: the SH3 domain of ponsin, using data from a multianalyzer diffractometer. To demonstrate that cross-species molecular replacement using image plate data is also possible, we present the solution of hen egg white lysozyme using the 60% identical human lysozyme (PDB code: 1LZ1) as the search model. Due to the high incidence of overlaps in powder patterns, especially in more complex structures, we have used extracted intensities from five data sets taken at different salt concentrations in a multi-pattern Pawley refinement. The use of image plates severely increases the overlap problem due to lower detector resolution, but radiation damage effects are minimized with shorter exposure times and the fact that the entiremore » pattern is obtained in a single exposure. This image plate solution establishes the robustness of powder molecular replacement resulting from different data collection techniques.« less","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84393394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dislocations are known for their peculiar effects on the diffraction profiles. Each given dislocation type, produces specific anisotropic line broadening basically determined by the so-called contrast factor (CF). Owing to the lack of a suitable mathematical frame to deal with dislocations in crystal of any symmetry, CFs have been so far determined for high symmetry materials. In this work we present the main points of a general approach for determining CF, as well as a specific application to scheelite CaWO4.
{"title":"Diffraction contrast factor of dislocations: The case of scheelite CaWO4","authors":"J. Martinez-Garcia, M. Leoni, P. Scardi","doi":"10.1524/ZKSU.2009.0013","DOIUrl":"https://doi.org/10.1524/ZKSU.2009.0013","url":null,"abstract":"Dislocations are known for their peculiar effects on the diffraction profiles. Each given dislocation type, produces specific anisotropic line broadening basically determined by the so-called contrast factor (CF). Owing to the lack of a suitable mathematical frame to deal with dislocations in crystal of any symmetry, CFs have been so far determined for high symmetry materials. In this work we present the main points of a general approach for determining CF, as well as a specific application to scheelite CaWO4.","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74842391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Dercz, L. Paja̧k, K. Prusik, R. Pielaszek, J. Malinowski
Materials with MgO nanocrystallites were prepared by sol-gel synthesis. Alcogels were dried either supercritically at 538 K or in supercritical CO2. Conventional drying was also applied. Structure studies were performed by X-ray diffraction, scanning and transmis- sion electron microcopies. Nitrogen adsorption/desorption measurements were also per- formed. Calcination of dry gels at 723 K under vacuum yielded MgO nanocrystallites. In the studied materials the presence of the amorphous phase was observed. It is also stated that MgO nanocrystallites are immersed in an amorphous matrix. Morphology of supercritically dried samples is similar; rough surface of powder particles is observed. Powder particles of conventionally dried sample are more compact. Size of MgO crystallites is generally similar for all samples and equal to about 7 nm despite the drying conditions of alcogels. The specific surface area and the volume of mesopores are the great- est for the sample supercritically dried at 538 K.
{"title":"Nanocrystalline MgO powder materials prepared by sol-gel studied by X-ray diffraction and electron microscopy","authors":"G. Dercz, L. Paja̧k, K. Prusik, R. Pielaszek, J. Malinowski","doi":"10.1524/ZKSU.2009.0037","DOIUrl":"https://doi.org/10.1524/ZKSU.2009.0037","url":null,"abstract":"Materials with MgO nanocrystallites were prepared by sol-gel synthesis. Alcogels were dried either supercritically at 538 K or in supercritical CO2. Conventional drying was also applied. Structure studies were performed by X-ray diffraction, scanning and transmis- sion electron microcopies. Nitrogen adsorption/desorption measurements were also per- formed. Calcination of dry gels at 723 K under vacuum yielded MgO nanocrystallites. In the studied materials the presence of the amorphous phase was observed. It is also stated that MgO nanocrystallites are immersed in an amorphous matrix. Morphology of supercritically dried samples is similar; rough surface of powder particles is observed. Powder particles of conventionally dried sample are more compact. Size of MgO crystallites is generally similar for all samples and equal to about 7 nm despite the drying conditions of alcogels. The specific surface area and the volume of mesopores are the great- est for the sample supercritically dried at 538 K.","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76324398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A simulation of a protein powder diffraction pattern was stunning in the apparent amount of information that was seen. A subsequent experiment on metmyoglobin gave a powder diffraction pattern that showed very little sample broadening; the peak widths were essentially limited by the instrument resolution. The challenge is to make use of this in protein structure analysis. This talk will recall some of those early experiments and data analyses as well as an overview of current progress and future possibilities.
{"title":"Characterization of proteins by powder diffraction.","authors":"R. Dreele","doi":"10.1524/ZKSU.2009.0004","DOIUrl":"https://doi.org/10.1524/ZKSU.2009.0004","url":null,"abstract":"A simulation of a protein powder diffraction pattern was stunning in the apparent amount of information that was seen. A subsequent experiment on metmyoglobin gave a powder diffraction pattern that showed very little sample broadening; the peak widths were essentially limited by the instrument resolution. The challenge is to make use of this in protein structure analysis. This talk will recall some of those early experiments and data analyses as well as an overview of current progress and future possibilities.","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78210287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Levine, B. Larson, J. Tischler, P. Geantil, M. E. Kassner, W. Liu, M. Stoudt
Energy scanned, sub-micrometer X-ray beams were used to obtain diffraction line profiles from individual dislocation cells in copper single crystals deformed in compression. Sub-micrometer depth resolution was provided by translating a wire through the diffracted beams and using triangulation to determine the depths of the diffracting volumes. Connection to classic volume-averaged results was made by adding the line profiles from 52 spatially resolved dislocation cell measurements. The resulting sub profile is smooth and symmetric, in agreement with early assumptions; the mean strain and full width half maximum are consistent with the average of the parameters extracted from the more exact individual dislocation cell measurements.
{"title":"Impact of dislocation cell elastic strain variations on line profiles from deformed copper.","authors":"L. Levine, B. Larson, J. Tischler, P. Geantil, M. E. Kassner, W. Liu, M. Stoudt","doi":"10.1524/ZKSU.2008.0008","DOIUrl":"https://doi.org/10.1524/ZKSU.2008.0008","url":null,"abstract":"Energy scanned, sub-micrometer X-ray beams were used to obtain diffraction line profiles from individual dislocation cells in copper single crystals deformed in compression. Sub-micrometer depth resolution was provided by translating a wire through the diffracted beams and using triangulation to determine the depths of the diffracting volumes. Connection to classic volume-averaged results was made by adding the line profiles from 52 spatially resolved dislocation cell measurements. The resulting sub profile is smooth and symmetric, in agreement with early assumptions; the mean strain and full width half maximum are consistent with the average of the parameters extracted from the more exact individual dislocation cell measurements.","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81680632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-31DOI: 10.1524/9783486992540-072
T. Aitasalo, A. Hietikko, J. Hölsä, M. Lastusaari, J. Niittykoski, T. Piispanen
{"title":"Crystal Structure of the Ba3MgSi2O8:Mn2+,Eu2+ phosphor for white light emitting diodes","authors":"T. Aitasalo, A. Hietikko, J. Hölsä, M. Lastusaari, J. Niittykoski, T. Piispanen","doi":"10.1524/9783486992540-072","DOIUrl":"https://doi.org/10.1524/9783486992540-072","url":null,"abstract":"","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80365032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-12-31DOI: 10.1524/ZKSU.2007.2007.SUPPL_26.563
R. Toro, G. D. Delgado, A. Bahsas, J. M. Delgado
{"title":"The presence of polymorphism in oxytetracycline hydrochloride shown by X-ray powder diffraction techniques","authors":"R. Toro, G. D. Delgado, A. Bahsas, J. M. Delgado","doi":"10.1524/ZKSU.2007.2007.SUPPL_26.563","DOIUrl":"https://doi.org/10.1524/ZKSU.2007.2007.SUPPL_26.563","url":null,"abstract":"","PeriodicalId":23897,"journal":{"name":"Zeitschrift Fur Kristallographie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72671814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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