Experimental determinations of the quantity M//spl rho/ for silicon single crystals used in the determination of the Avogadro constant

Abstract

Considerable improvements in the measurements of the molar mass M(Si) of silicon crystals combined with high-accuracy densities (/spl rho/) of the same crystals, have yielded experimental M(Si)//spl rho/ values resulting from the PTB-IRMM, the IMGC-IRMM and the NRLM-IRMM projects for the redetermination of Avogadro's Constant. These M(Si)//spl rho/ values are compared with attributed uncertainties, in relation to the supposition of constancy M(Si)//spl rho/ for silicon.<>