Title :
Toward the Avogadro constant-preliminary results on the molar volume of silicon
Author :
Sacconi, Attilio ; Peuto, Anna M. ; Pasin, Walter ; Panciera, Renzo ; Lenaers, Guido ; Valkiers, Staf ; van den Berg, Max ; De Bievre, P.
Author_Institution :
Inst. di Metrol., Torino, Italy
fDate :
4/1/1989 12:00:00 AM
Abstract :
The silicon molar volume has been measured through atomic weight and density measurements. Mass spectrometric determination of the isotopic composition was performed on two differently grown samples by comparison with the US National Bureau of Standards (NBS) reference material SRM 990. The density of specimens from the same crystals was obtained through direct mass and dimension measurements on one single-crystal sphere and through hydrostatic comparison for another sphere. Compatibility with previous measurements was checked through hydrostatic comparison with IMGC Zerodur density standards. The two molar volume determinations differ by 0.14 p.p.m. The preliminary value obtained is 12.058, 843±0.000, 029 cm3/mol at 22.5°C and in vacuo
Keywords :
atomic mass; constants; density measurement; elemental semiconductors; silicon; volume measurement; Avogadro constant; IMGC Zerodur density standards; Si; US National Bureau of Standards; atomic weight; density measurements; dimension measurements; hydrostatic comparison; isotopic composition; mass measurement; molar volume; reference material; Atomic measurements; Composite materials; Crystalline materials; Crystals; Density measurement; Mass spectroscopy; NIST; Silicon; Volume measurement; Weight measurement;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
