Browse by author
Lookup NU author(s): Professor Peter Cumpson, Dr Naoko Sano
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
The stability of reference masses has been a long-standing concern within the SI. More recently the requirements of potential non-artefact realizations of the kilogram have added gold and its alloys to the platinum alloys that have historically been the focus of attention. Previously we proposed UV/ozone cleaning of standard-mass surfaces to improve stability with respect to carbonaceous contamination. Since then both NPL and BIPM have constructed prototypes of UV/ozone apparatus for cleaning kilogram standards. We have therefore tested a combined solvent wash and UV/ozone procedure, UVOPS or 'UV/ozone with pre-wash and stabilization', on both platinum and gold surfaces. X-ray photoelectron spectroscopy (XPS) shows this to be very successful in removing even gross contamination from these noble metal surfaces. Oxidation is negligible, limited to the outermost layer of noble metal atoms, and terminates at a level that is within the uncertainty of mass comparisons at the 1 kg level. This oxide has been seen in some earlier XPS studies but not others—we show that decomposition of the oxide by x-rays at XPS energies may be responsible for this disparity.
Author(s): Cumpson PJ, Sano N
Publication type: Article
Publication status: Published
Journal: Metrologia
Year: 2013
Volume: 50
Issue: 1
Pages: 27-36
Print publication date: 07/01/2013
ISSN (print): 0026-1394
ISSN (electronic): 1681-7575
Publisher: Institute of Physics Publishing
URL: http://dx.doi.org/10.1088/0026-1394/50/1/27
DOI: 10.1088/0026-1394/50/1/27
Notes: Metrologia is the main international journal in Metrology. As of 14/1/2013 this article is reported by the journal website as the most read (i.e. downloaded) article in this journal over the last 30 days, despite only having been published for 7 days, i.e. more than four times the download rate of the second most read article in the journal.
Altmetrics provided by Altmetric
