Low cation coordination in oxide melts

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.112.157801· OSTI ID:1128979

Skinner, Lawrie ^[1]; Benmore, Chris J ^[2]; Du, Jincheng ^[3]; Weber, Richard ^[2]; Neuefeind, Joerg C ^[4]; Tumber, Sonia ^[5]; Parise, John B ^[6]

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1. State University of New York, Stony Brook
2. Argonne National Laboratory (ANL)
3. University of North Texas
4. ORNL
5. Materials Development, Inc., Evanston, IL
6. Stony Brook University (SUNY)

The complete set of Faber-Ziman partial pair distribution functions for a rare earth oxide liquid were measured for the first time by combining aerodynamic levitation, neutron diffraction, high energy x-ray diffraction and isomorphic substitution using Y2 O3 and Ho2 O3 melts. The average Y- O coordination is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2 O3 (or Ho2 O3 ). Investigation of high temperature La2 O3 , ZrO2 , SiO2 , and Al2 O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation- oxygen coordination. These measurements suggest a general trend towards lower M-O coordination compared to their crystalline counterparts. It is found that this coordination number drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1128979
• Journal Information: Physical Review Letters, Vol. 112, Issue 15; ISSN 0031--9007
• Country of Publication: United States
• Language: English