Title: Determination of the Avogadro Constant by Counting the Atoms in a 28Si Crystal
Authors: ANDREAS B.AZUMA Y.BARTL G.BECKER P.BETTIN H.BORYS M.BUSCH I.GRAY M.FUCHS P.FUJII K.FUJIMOTO H.KESSLER E.KRUMREY M.KUETGENS U.KURAMOTO N.MANA G.MANSON P.MASSA E.MIZUSHIMA S.NICOLAUS A.PICARD A.PRAMANN A.RIENITZ O.SCHIEL D.VALKIERS StafWASEDA A.
Citation: PHYSICAL REVIEW LETTERS vol. 106 no. 3 p. 030801 (1-4)
Publisher: AMER PHYSICAL SOC
Publication Year: 2011
JRC N°: JRC57140
ISSN: 0031-9007
URI: http://publications.jrc.ec.europa.eu/repository/handle/JRC57140
DOI: 10.1103/PhysRevLett.106.030801
Type: Articles in Journals
Abstract: The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by counting the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, NA=6.022 140 78(18)×1023  mol-1, is the most accurate input datum for a new definition of the kilogram.
JRC Institute:Institute for Reference Materials and Measurements

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.