Rare earth elements in silicate glass / melt systems: II. Interactions of La, Gd, and Yb with halogens

Computer Science

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

8

Scientific paper

The local geometry of sites occupied by trace amounts (0.2 wt%) of La 3+ , Gd 3+ , and Yb 3+ was examined as a function of composition in quenched silicate melts containing fluorine or chlorine using Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The glass compositions examined were albite (NaAlSi 3 O 8 ), sodium trisilicate (Na 2 Si 3 O 7 ), and a peralkaline composition (Na 3.3 AlSi 7 O, 17 ) approximately halfway between the two. The volatile contents were approximately 1-2 wt% fluorine or. chlorine. Our results indicate that La, Gd, and Yb form complexes with fluorine in the glasses studied. Gd and Yb are coordinated by eight fluorines with no apparent oxygen neighbors [ d ( Gd - F ) = 2.30Å; d ( Yb - F ) = 2.23 Å]. La appears to form mixed O-F complexes consisting of eight ligands approximately evenly divided between fluorine and oxygen [ d ( La - O ) = 2.45 Å; d ( La - F ) = 2.46 Å]. We found no evidence for REE-Cl complexes in the compositions studied. The rare earth sites in chlorine-containing melts are, however, more regular than those in volatile-free melts, suggesting that Cl acts to depolymerize the tetrahedral network. Fluorine, because of complex formation and its effect on melt structure and chlorine, because of its effect on melt structure, should both act to decrease crystal-melt partition coefficients of rare earths.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Rare earth elements in silicate glass / melt systems: II. Interactions of La, Gd, and Yb with halogens does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Rare earth elements in silicate glass / melt systems: II. Interactions of La, Gd, and Yb with halogens, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rare earth elements in silicate glass / melt systems: II. Interactions of La, Gd, and Yb with halogens will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1615399

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.