TY - JOUR A1 - Belsey, N. A. A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Araujo, J. R. A1 - Bock, B. A1 - Brüner, P. A1 - Castner, D. G. A1 - Ceccone, G. A1 - Counsell, J. D. P. A1 - Dietrich, Paul M. A1 - Engelhardt, M. H. A1 - Fearn, S. A1 - Galhardo, C. E. A1 - Kalbe, H. A1 - Kim, J. W. A1 - Lartundo-Rojas, L. A1 - Luftman, H. S. A1 - Nunney, T. S. A1 - Pseiner, J. A1 - Smith, E. F. A1 - Spampinato, V. A1 - Sturm, J. M. A1 - Thomas, A. G. A1 - Treacy, J. P. W. A1 - Veith, L. A1 - Wagstaffe, M. A1 - Wang, H. A1 - Wang, M. A1 - Wang, Y.-C. A1 - Werner, W. A1 - Yang, L. A1 - Shard, A. G. T1 - Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS JF - The Journal of Physical Chemistry C N2 - We report the results of a Versailles Project on Advanced Materials and Standards (VAMAS) interlaboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage, or sample preparation resulted in a variability in thickness of 53%. The calculation method chosen by XPS participants contributed a variability of 67%. However, variability of 12% was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors since this contributed a variability of 33%. The results from the LEIS participants were more consistent, with variability of less than 10% in thickness, and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films, and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results. KW - VAMAS KW - Interlaboratory Study KW - Nanoparticle coating KW - XPS KW - LEIS KW - shell thicknss and chemistry PY - 2016 UR - http://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.6b06713 DO - https://doi.org/10.1021/acs.jpcc.6b06713 IS - 120 SP - 24070 EP - 24079 PB - ACS Publications AN - OPUS4-38428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A. P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.F. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J. L. A1 - Chen, J. A1 - Counsell, J..D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cartazar-Martínez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Shard, A.G. T1 - Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene JF - Journal of Vacuum Science & Technology A N2 - We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Intensity scale calibration KW - Reference spectra KW - Low-density polyethylene (LDPE) PY - 2020 DO - https://doi.org/10.1116/6.0000577 VL - 38 IS - 6 SP - 063208 AN - OPUS4-51655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Anker, A. S. A1 - Annadurai, V. A1 - Balazs, D. M. A1 - Bienert, Ralf A1 - Bouwman, W. G. A1 - Breßler, Ingo A1 - Breternitz, J. A1 - Brok, E. S. A1 - Bryant, G. A1 - Clulow, A. J. A1 - Crater, E. R. A1 - De Geuser, F. A1 - Del Giudice, A. A1 - Deumer, J. A1 - Disch, S. A1 - Dutt, S. A1 - Frank, K. A1 - Fratini, E. A1 - Garcia, P. R. A. F. A1 - Gilbert, E. P. A1 - Hahn, Marc Benjamin A1 - Hallett, J. A1 - Hohenschutz, M. A1 - Hollamby, M. A1 - Huband, S. A1 - Ilavsky, J. A1 - Jochum, J. K. A1 - Juelsholt, M. A1 - Mansel, B. W. A1 - Penttilä, P. A1 - Pittkowski, R. K. A1 - Portale, G. A1 - Pozzo, L. D. A1 - Rochels, L. A1 - Rosalie, Julian M. A1 - Saloga, Patrick E. J. A1 - Seibt, S. A1 - Smith, A. J. A1 - Smith, G. N. A1 - Spiering, G. A. A1 - Stawski, Tomasz M. A1 - Taché, O. A1 - Thünemann, Andreas A1 - Toth, K. A1 - Whitten, A. E. A1 - Wuttke, J. T1 - The human factor: results of a small-angle scattering data analysis round robin JF - Journal of Applied Crystallography N2 - A round-robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5% and half of the population width entries within 40%. Due to the added complexity of the structure factor, far fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 and 86%, respectively. This round-robin experiment highlights several causes for the discrepancies, for which solutions are proposed. KW - Round Robin KW - Data analysis KW - Small-angle scattering KW - Nanomaterials KW - Interlaboratory comparability KW - Nanostructure quantification KW - Methodology KW - MOUSE PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587091 DO - https://doi.org/10.1107/S1600576723008324 VL - 56 IS - 6 SP - 1618 EP - 1629 PB - International Union of Crystallography (IUCr) AN - OPUS4-58709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Anker, A. S. A1 - Balazs, D. M. A1 - Beyer, F. L. A1 - Bienert, Ralf A1 - Bouwman, W. G. A1 - Breßler, Ingo A1 - Breternitz, J. A1 - Brok, E. S. A1 - Bryant, G. A1 - Clulow, A. J. A1 - Crater, E. R. A1 - De Geuser, F. A1 - Giudice, A. D. A1 - Deumer, J. A1 - Disch, S. A1 - Dutt, S. A1 - Frank, K. A1 - Fratini, E. A1 - Gilbert, E. P. A1 - Hahn, Marc Benjamin A1 - Hallett, J. A1 - Hohenschutz, Max A1 - Hollamby, M. J. A1 - Huband, S. A1 - Ilavsky, J. A1 - Jochum, J. K. A1 - Juelsholt, M. A1 - Mansel, B. W. A1 - Penttilä, P. A1 - Pittkowski, R. K. A1 - Portale, G. A1 - Pozzo, L. D. A1 - Ricardo de Abreu Furtado Garcia, P. A1 - Rochels, L. A1 - Rosalie, Julian M. A1 - Saloga, P. E. J. A1 - Seibt, S. A1 - Smith, A. J. A1 - Smith, G. N. A1 - Annadurai, V. A1 - Spiering, G. A. A1 - Stawski, Tomasz A1 - Taché, O. A1 - Thünemann, Andreas A1 - Toth, K. A1 - Whitten, A. E. A1 - Wuttke, J. T1 - The human factor: results of a small-angle scattering data analysis Round Robin T2 - arXiv.org N2 - A Round Robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions, and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5 % and half of the population width entries within 40 %, respectively. Due to the added complexity of the structure factor, much fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 % and 86 % respectively. This Round Robin experiment highlights several causes for the discrepancies, for which solutions are proposed. KW - Round Robin KW - Sall-angle scattering KW - Nanostructure quantification KW - Nanostructure KW - SAXS KW - MOUSE KW - X-ray scattering KW - Size distribution KW - Nanoparticles PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571342 DO - https://doi.org/10.48550/arXiv.2303.03772 SP - 1 EP - 23 PB - Cornell University CY - New York AN - OPUS4-57134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hernández-Nava, E. A1 - Smith, C.J. A1 - Derguti, F. A1 - Tammas-Williams, S. A1 - Léonard, Fabien A1 - Withers, P. J. A1 - Todd, I. A1 - Goodall, R. T1 - The effect of density and feature size on mechanical properties of isostructural metallic foams produced by additive manufacturing JF - Acta Materialia N2 - Simple models describing the relationship between basic mechanical properties and the relative density of various types of porous metals (such as foams, sponges and lattice structures) are well established. Carefully evaluating these relationships experimentally is challenging, however, because of the stochastic structure of foams and the fact that it is difficult to systematically isolate density changes from variations in other factors, such as pore size and pore distribution. Here a new method for producing systematic sets of stochastic foams is employed based on electron beam melting (EBM) additive manufacturing (AM). To create idealised structures, structural blueprints were reverse-engineered by inverting X-ray computed tomographs of a randomly packed bed of glass beads. This three-dimensional structure was then modified by computer to create five foams of different relative density ρr, but otherwise consistent structure. Yield strength and Young’s modulus have been evaluated in compression tests and compared to existing models for foams. A power of 3 rather than a squared dependence of stiffness on relative density is found, which agrees with a recent model derived for replicated foams. A similar power of 3 relation was found for yield strength. Further analysis of the strength of nominally fully dense rods of different diameters built by EBM AM suggest that surface defects mean that the minimum size of features that can be created by EBM with similar strengths to machined samples is ∼1 mm. KW - Metal foam KW - Cellular solids KW - Reverse engineering KW - Open-cell foam KW - X-ray computed tomography PY - 2015 DO - https://doi.org/10.1016/j.actamat.2014.10.058 SN - 1359-6462 VL - 85 SP - 387 EP - 395 AN - OPUS4-39071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hernández-Nava, E. A1 - Smith, C.J. A1 - Derguti, F. A1 - Tammas-Williams, S. A1 - Léonard, Fabien A1 - Withers, P. J. A1 - Todd, I. A1 - Goodall, R. T1 - The effect of defects on the mechanical response of Ti-6Al-4V cubic lattice structures fabricated by electron beam melting JF - Acta Materialia N2 - Electron Beam Melting (EBM) as a means of Additive Manufacturing (AM), is of interest for the fabrication of intricate geometries for cellular materials in areas where complex architectures are needed, e.g. biomedical implants. Most studies have focused on specific geometries and so the effect of the structure on mechanical performance is not well understood. Many kinds of micro- and macro-scale defects can arise in additively manufactured components, so assessment of their influence on properties is needed. In this work, lattices of Ti-6Al-4V having a cubic structure have been manufactured by EBM, and the effect of heat treatments above and below the β-transus temperature on microstructure and compression response have been investigated. The former modifies only slightly the α + β structure and mechanical performance whereas the latter leads to coarse alternating α and β lamellae packets and α at the prior grain boundaries with a 10% loss in yield strength. The variation in the compressive yield stress with strut diameter is in good accord with simple models based on compressive deformation rather than shearing or buckling. Internal pores for struts aligned with the build direction are found around the edges of the solid form, in regions which seem to be associated with the EB scan pattern. Struts normal to the build direction show more significant defects but their redundancy means that they do not compromise the compressive performance in the build direction. Using a particle size in the range 45–100 μm minimum weld-track sizes were experimentally and numerically identified to be 176 and 148 μm in depth respectively with a depth-to-width ratio of 0.55. This produced a beam pass of the order of 300 μm oversizing small features (struts of 0.4 and 0.6 mm nominal diameter) when a contour around the strut periphery was applied. KW - Cellular solids KW - Additive manufacturing KW - Titanium alloy KW - Mechanical properties KW - X-ray computed tomography PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-390686 DO - https://doi.org/10.1016/j.actamat.2016.02.029 SN - 1359-6454 VL - 108 SP - 279 EP - 292 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-39068 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hollamby, M. J. A1 - Smith, C. F. A1 - Britton, M. M. A1 - Danks, A. E. A1 - Schnepp, Z. A1 - Grillo, I. A1 - Pauw, Brian Richard A1 - Kishimura, A. A1 - Nakanishi, T. T1 - The aggregation of an alkyl–C60 derivative as a function of concentration, temperature and solvent type JF - Physical Chemistry Chemical Physics N2 - Contrast-variation small-angle neutron scattering (CV-SANS), small-angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) measurements of diffusion and isothermal titration calorimetry (ITC) are used to gain insight into the aggregation of an alkyl–C60 derivative, molecule 1, in n-hexane, n-decane and toluene as a function of concentration and temperature. Results point to an associative mechanism of aggregation similar to other commonly associating molecules, including non-ionic surfactants or asphaltenes in non-aqueous solvents. Little aggregation is detected in toluene, but small micelle-like structures form in n-alkane solvents, which have a C60-rich core and alkyl-rich shell. The greatest aggregation extent is found in n-hexane, and at 0.1 M the micelles of 1 comprise around 6 molecules at 25 °C. These micelles become smaller when the concentration is lowered, or if the solvent is changed to n-decane. The solution structure is also affected by temperature, with a slightly larger aggregation extent at 10 °C than at 25 °C. At higher concentrations, for example in solutions of 1 above 0.3 M in n-decane, a bicontinuous network becomes apparent. Overall, these findings aid our understanding of the factors driving the assembly of alkyl–π-conjugated hydrophobic amphiphiles such as 1 in solution and thereby represent a step towards the ultimate goal of exploiting this phenomenon to form materials with well-defined order. KW - Complex Molecular Systems KW - Supramolecules KW - Scattering PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-442977 DO - https://doi.org/10.1039/C7CP06348B VL - 20 IS - 5 SP - 3773 EP - 3380 PB - RSC AN - OPUS4-44297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, S.J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A.P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.P. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J.L. A1 - Chen, J. A1 - Counsell, J.D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cortazar-Martinez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Compean-Gonzalez, C.L. A1 - Ceccone, G. A1 - Shard, A.G. T1 - ERRATUM: “Versailles project on advanced materials and standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene” [J. Vac. Sci. Technol. A 38, 063208 (2020)] JF - Journal of Vacuum Science & Technology A N2 - The lead authors failed to name two collaborators as co-authors. The authors listed should include: Miss Claudia L. Compean-Gonzalez (ORCID: 0000-0002-2367-8450) and Dr. Giacomo Ceccone (ORCID: 0000-0003-4637-0771). These co-authors participated in VAMAS project A27, provided data that were analyzed and presented in this publication (and supporting information), and reviewed the manuscript before submission. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Low-density polyethylene PY - 2021 DO - https://doi.org/10.1116/6.0000907 VL - 39 IS - 2 SP - 027001 PB - American Vacuum Society AN - OPUS4-52380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -