Experimental determination of Os metal/silicate partitioning
Borisov, Alexander; Palme, Herbert
published: May 1, 1998
ArtNo. ESP154017202011, Price: 29.00 €
We report here the first experimental results on the partitioning of Os between metal (Ni-rich OsNi alloys) and silicate melt of anorthite-diopside eutectic composition at 1400 °C and one atmosphere total pressure and at oxygen fugacities ranging from 10-8 to 10-12 atm. Experiments were done by equilibrating OsNi metal loops with silicate melt. Metal and glass were separately analyzed by instrumental neutron activation analysis (INAA) and metal/silicate partition coefficients for Ni and Os (ONi, DoS) were calculated. The metal/silicate partition coefficients of Ni obtained in this study are in agreement with the results of earlier experiments. In a log DNi vs. log f02 diagram the results can be fitted to a straight line with a slope of - 0.45, close to -1/2, implying an effective valence of Ni in the silicate melt of around + 2.