Structural transformation in Ni-bearing Na2Si2O5 glass and melt

Details Structural transformation in Ni-bearing Na2Si2O5 glass and melt Structural transformation in Ni-bearing Na2Si2O5 glass and melt

Sep 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994georl..21.1931f&link_type=abstract

Geophysical Research Letters (ISSN 0094-8276), vol. 21, no. 18, p. 1931-1934

Physics

5

Chemical Composition, Glass, Melts (Crystal Growth), Nickel Compounds, Pressure Effects, Absorption Spectroscopy, Fine Structure, Geochemistry, Mathematical Models, X Ray Spectroscopy

Scientific paper

The coordination environment around Ni at minor concentration levels (2 wt. % NiO) in Na2Si2O5 glass and melt (293-1250K) has been investigated by Ni K-edge X-ray Absorption Fine Structure (XAFS) spectroscopy. X-ray Absorption Near Edge Structure (XANES) spectra indicate that both Ni IV and Ni V occur in the glass, whereas Ni IV is dominant in the melt. The average anharmonic Ni-O distances derived from XAFS spectra of the glass at 293 K and the melt above 1150 K are 2.00 (+/- 0.02) and 1.97 (+/- 0.02) A, respectively. The Ni-O distance in the glass is consistent with a mixture of Ni IV and Ni V whereas that in the melt is consistent with dominantly Ni V, suggesting a Ni-coordination change during glass melting. This major change in Ni coordination indicates significant reorganization of the melt during quenching and crystallization. These observations for a compositionally- simple melt/glass system may help explain the enrichment of Ni in early-formed igneous materials. They also suggest the possiblity of a pressure-induced coordination change around Ni in the mantle which may influence geochemical modeling of the deep Earth.

Affiliated with

Also associated with

No associations

Rating

Structural transformation in Ni-bearing Na2Si2O5 glass and melt 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 Structural transformation in Ni-bearing Na2Si2O5 glass and melt, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structural transformation in Ni-bearing Na2Si2O5 glass and melt will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1789586