Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS.
We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) inter-laboratory 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.
National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK.
Natalie A
NA
Belsey
National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK.
David J H
DJ
Cant
National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK.
Caterina
C
Minelli
Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Divisão de Metrologia de Materiais (Dimat) Avenida Nossa Senhora das Graças, 50 Duque de Caxias, RJ 25250-020, Brazil.
Joyce R
JR
Araujo
Tascon GmbH, Mendelstr. 17, D-48149 Münster, Germany.
Bernd
B
Bock
ION-TOF GmbH, Heisenbergstr. 15, 48149 Münster, Germany.
Philipp
P
Brüner
National ESCA and Surface Analysis Center for Biomedical Problems, Departments of Bioengineering and Chemical Engineering, University of Washington, Seattle, WA 98195-1653, USA.
David G
DG
Castner
European Commission Joint Research Centre, Institute for Health and Consumer Protection, Nanobiosciences Unit, Via E. Fermi 2749, 21027 Ispra, Italy.
Giacomo
G
Ceccone
Kratos Analytical Ltd., Wharfside, Trafford Wharf Road, Manchester M17 1GP, UK.
Jonathan D P
JD
Counsell
BAM Federal Institute for Materials Research and Testing (BAM 6.1), Unter den Eichen 44-46, D-12203 Berlin, Germany.
Paul M
PM
Dietrich
Pacific Northwest National Laboratory, EMSL, Richland, WA 99352, USA.
Mark H
MH
Engelhard
Department of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Sarah
S
Fearn
Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Divisão de Metrologia de Materiais (Dimat) Avenida Nossa Senhora das Graças, 50 Duque de Caxias, RJ 25250-020, Brazil.
Carlos E
CE
Galhardo
Kratos Analytical Ltd., Wharfside, Trafford Wharf Road, Manchester M17 1GP, UK.
Henryk
H
Kalbe
Korea Research Institute of Standards and Science, 267 Gajeong-ro, Daejeon 34113, Korea.
Jeong
J
Won Kim
Instituto Politécnico Nacional, Centro de Nanociencias y Micro y Nanotecnologías, UPALM, Zacatenco, México D.F. CP. 07738, México.
Luis
L
Lartundo-Rojas
Surface Analysis Facility, Lehigh University, 7 Asa Drive, Bethlehem, PA 18015. USA.
Henry S
HS
Luftman
Thermo Fisher Scientific, Unit 24, The Birches Industrial Estate, Imberhorne Lane, East Grinstead, West Sussex, RH19 1UB, UK.
Tim S
TS
Nunney
Institut fuer Angewandte Physik, TU Vienna, Wiedner Hauptstr 8-10, A 1040 Vienna, Austria.
Johannes
J
Pseiner
Nanoscale and Microscale Research Centre, School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Emily F
EF
Smith
National ESCA and Surface Analysis Center for Biomedical Problems, Departments of Bioengineering and Chemical Engineering, University of Washington, Seattle, WA 98195-1653, USA.
Valentina
V
Spampinato
Industrial Focus Group XUV Optics, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, the Netherlands.
Jacobus M
JM
Sturm
School of Materials and Photon Science Institute, University of Manchester, Manchester, M13 9PL, UK.
Andrew G
AG
Thomas
Thermo Fisher Scientific, Unit 24, The Birches Industrial Estate, Imberhorne Lane, East Grinstead, West Sussex, RH19 1UB, UK.
Jon P W
JP
Treacy
Tascon GmbH, Mendelstr. 17, D-48149 Münster, Germany.
Lothar
L
Veith
School of Materials and Photon Science Institute, University of Manchester, Manchester, M13 9PL, UK.
Michael
M
Wagstaffe
National Institute of Metrology, Beijing 100029, P. R. China.
Hai
H
Wang
National Institute of Metrology, Beijing 100029, P. R. China.
Meiling
M
Wang
ION-TOF GmbH, Heisenbergstr. 15, 48149 Münster, Germany.
Yung-Chen
YC
Wang
Institut fuer Angewandte Physik, TU Vienna, Wiedner Hauptstr 8-10, A 1040 Vienna, Austria.
Wolfgang
W
Werner
Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, China.
Li
L
Yang
National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK.
Alexander G
AG
Shard